First question we need to know to help is whether you need a replacement (insert) window or new construction window. If the existing window frame and exterior casings are in good shape then you can use an insert. I will address your other questions:

I'm currently interested in Marvin Ultimate, infinity, integrity and Andersen 400, A, and E series (haven't priced anything out yet). Not really interested in any all vinyl options.

Good choices. You might also consider Kolbe and possibly Loewen if it is available in the Chicago area.

- I will be looking at the U Factor, SHGC, and Air leakage #'s for each of these windows? is there anything else I should be looking at (besides the material and look of them). I really want an efficient window. My house (especially back) gets hit with some major winds.

I think you have this covered. I think Low e 272 or some variation of that would be your glass of choice in the Chicago area. Possibly consider warranties but for the manufacturers you mentioned, they are comparable.

- Does it matter how wide the actually casing is for each window? It looks like some of these windows have much wider casings than the other?

Not sure what you are asking. I think you are asking about the amount of glass area relative to frame area. If your windows are on the small size, then you will want to maximize the amount of glass and not get a "bulky" window, Otherwise, I don't think this should be a big concern.

- I'm assuming each window has different types of glass (Low E, etc) and different gas options (argon, etc). Are there options or will a particular window (i.e. Marvin Infinity come with a specific glass and gas)? What should I be looking at related to the glass and different gas options?

Again, I think Low e 272 with argon would suffice. You might want to consider tri pane but you also need look at the payback for the additional expense. Tri pane will also limit you somewhat with the complete array of products and sizes from each manufacturer.

- For the grills and/or divided lites, is there advantages to having them between the glass vs. on the exterior/interior? In other words, is this purely for cosmetics or does one option offer a more efficient window?

For the best look, SDL is the way to go for the divided lites but if ease of cleaning is a priority, removable interior grills or GBGs (Grills Between the Glass) would be the best option and less expensive.

I cannot help you with the last two questions as I am on the West Coast.

I'm planning to do a full replacement on these windows. Regarding the low e windows, trying to figure out if it's worth it to upgrade to low e3. (Low e2 - 272 is standard). I'll also look at triple pane (But probably too expensive)

For the casing size, I mean the overall thickness of the frame of the window. I've noticed some are about 3 inches and others are 4 or 5 inches. (I hope I'm explaining this correctly).

Thanks for for your help.

A well engineered casement should be pretty darn tight so I would imagine the numbers (air infiltration) should be pretty consistent across the board if we are talking about similar quality products.

friedajune is 100% correct that you don't need Low-e 366 in your region. 272 is the right coating in your case.

I'm getting estimates from several local retail shops next week. I'd love to get some recommendations on who to use or who to avoid. Regarding the Marvin line, will there be a big difference in price between, integrity, inifinity, and ultimate lines? How about between Andersen 400 series and Marvin integrity?

You should see a difference in price between all series and a difference in price in the same series from different dealers. i would expect the 400 and integrity to be the lowest.

Wiylf like to know if you find the actual air infiltration numbers on those windows , it is not easy.

What what would be a better window the integrity or 400 series?

I think that will more so come down to which window you like the look of better. Both are pretty well built units.

Because you are looking at casements, be aware that the 400 has a vinyl wrapped sash to the interior (it is usually hidden by the screen). Not a big deal if you order white and your interior is white but could be problematic as I have seen jobs blow up over this if client wants to stain or paint a different color.

friedajune - I see you choose Marvin Ultimates for windows. Why did you go with the integrity for your sliding door?

I currently have a patio door, but considering doing a slider instead?

Msujohn - I chose the Integrity Wood-Ultrex sliding glass door because I got a quote on the Marvin Ultimate and it was really high. I asked my contractor how can I get the price of the sliding glass door to be more affordable. He suggested the Integrity Wood-Ultrex, which as I mentioned above, was about 30% less. He did steer me away from the all-fiberglass Marvin Infinity, as he did not think that would go with the rest of my home, which has mostly Marvin Ultimate windows (I still have a few old Pellas left which I am replacing slowly). The Integrity Wood-Ultrex has the nice wood interior.

Furthermore, the Integrity's exterior being Marvin's fiberglass material, Ultrex, needs pretty much no maintenance. The Ultimates do have a couple more extras - nicer hardware, the track is slightly better (you'd have to see it in the showroom to see what I mean, but it didn't seem that significant to me), and the Ultimate is offered primed or painted, while the Integrity comes either painted or raw, but not primed.

My contractor sent me to the lumberyard where he gets the windows, to see the windows on display. I don't know how they are when you just walk in, but I went in mentioning my contractor's name and that he had sent me, and they spent a good amount of time to show me everything so that I can compare. This was really helpful in making me comfortable with the Integrity Wood-Ultrex.

I'm starting to get my quotes back and have noticed (as expected) the Ultimate line is significantly more expensive. I'm trying to decide if the cost is worth it or not. Do you mind me asking what lumberyard you went to? At this time, I'm only getting estimates from the "bigger" window places. It's amazing on how some push E2 or E3 glass. Some say "integrity" will be fine and others tell me to go with "ultimate". Decisions, decisions. If I knew some quality contractors, I would consider that as an option.

some push E2 or E3 glass

I find that odd in the Chicago area; as noted in posts above, LoE-366 is not needed. But even if you wanted it, LoE-366 is not much of an upcharge, so not a big profit point for the contractor, so why would he push it?

...what lumberyard you went to?

Lee Lumber. I actually went to 2 of their locations, one in Highland Park where they spent a good amount of time with me, and one on Pershing in Chicago (closer to where I work so I popped in on my lunch hour just to see something quickly; it's more of a real contractor's place than the Highland Park location which is more retail-oriented).

Also, if you are willing to drive up to Lake Bluff, Marvin has a "Design Gallery" there. I visited there a few years ago when I was first looking at switching out my old Pella windows. It used to be owned and run directly by Marvin, but I just checked the website and it appears it is now run by Evanston Lumber. I realize these locations are a long drive for you. http://estateswindowsltd.com/ It might be just as good to visit Next Windows which is near you and that I mentioned in my prior post above. http://www.nextdoorandwindow.com/windows/

These places may not be open on weekends, only M-F.

If I knew some quality contractors

Have you tried Angie's List?

I've been to Next Windows already to look at the window options. I'll check out Angie's list for some quality installers as well. Thanks for the tips.

I could be wrong, but from what I've read about the gas inside the window panes - it doesn't matter what it is because in a few years it will have disappeared. None of the window manufacturers give a warranty of more than a few years on the gas.

Gargamel is 100% wrong. A well designed window with a superior spacer system will maintain argon gas. Buy a cheap window and yes, it will more than likely come out.

Not quite true Gargamel (love the reference BTW). Most quality companies and glass manufacturers are looking for gas leakage rates of well below 5% perannum. There is no reason to think that the gas and insulating value should not last for well past 20 years on a quality window.

Well, it is certainly confusing ... here's Marvin's warranty (sorry it's so small!)

The primary issue with gas leakage in years past was the spacer permeability to the gas. The spacers have gotten much better at this point. If you have a catastrophic failure of the spacer these days, you will know it and it will be a covered warranty failure. In the case of capillary tubes, there is no way to effectively "seal" that glass space after the fact or ultimately ensure the gas cannot get out.

I'd reinforce the comments above. Does gas dissipate and therefore is not warrantied? Yes. As WoW stated however, those rates of dissipation in a quality product these days are very, very low. Some as low as 1% per year.

Well, in my opinion, it seems to me that for the thousands and thousands and thousands it costs to replace/install windows, the warranty should be longer than 20 years, which is what it appears to be for most windows. They are an expensive disposable product.

Totally depends on what product you are looking at. Many replacement window have lifetime and transferable warranties on them.

I guess it does. I would love to know which window manufacturer makes a window that lasts "MY" lifetime...everytime I've asked what "lifetime" meant I got the response "lifetime means the lifetime of the window", which of course is an entirely different thing...and none of them would commit to what that lifetime is (other than what's written in the warranty - 20 years). If there is a window out there that is guaranteed for 50-60 years, please let me know what it is...

I think you are being unrealistic and unreasonable. What in your home will last 50- 60 years? Usually roofs carry longest warranties in a home, but not 50-60 years. Are you really thinking that anything in your home will be good 50-60 years from now? Even if your home is built with granite blocks (is it?), even those will need to have entirely new tuckpointing well before 50-60 years. Your wiring, plumbing, insulation, driveway, etc. none will be good 50-60 years from now.

Friedajune - I don't think I said I expected anything in my home to last 50-60 years. However if something is labelled as "lifetime", I would expect something to last approximately that amount of time. Perhaps I interpreted "lifetime" incorrectly, otherwise just say "20 year warranty"

Welcome to the wonderful world of marketing, just read the fine print regardless if it says 20 years or lifetime.

Many states have defined "lifetime" as it pertains to product warranties for the protection and benefit of consumers. In my state of Wisconsin for instance, "lifetime" is legally defined as 30 years. Could a window made of an inorganic material (or even wood in some cases) last much longer than that? Absolutely, particularly if it is a quality product. That said, advances in technology along with some expected degradation of performance will typically make replacement of a product such as window make good sense around or even a little before that time period.... really does depend on the quality and performance level of the original choice.

Let me also add that in regard to "20 year warranties", that number is most often associated with wood windows, and is typically a 10/20 warranty. 20 years on glass only, 10 on everything else. This is in comparison to something like a vinyl window where many that are "lifetime", or 50 years, or whatever that number is, will apply to the entire product. As Todd said, it does come down to marketing, so it is highly advisable to read the warranty terms in detail of any product that you are considering

Very interesting about the consumer laws. I live in Canada and sometimes even trying to get a definition of "lifetime" is like pulling teeth, and sometimes it's not spelled out even in the small print. Farley windows (not that I would buy them) are like that - they say the window has a lifetime guarantee and when you ask what the lifetime is they say "for however long the window lasts" then when I ask "how long will it last", their response is "however long it lasts.