this is the product where the 'devil is in the details' stuff. Make sure that you are being quoted the extruded alum. stuff and not the rolled form products. Roll form, for the most part, is 'weaker' thus cheaper. Get a copy, read and understand their warranty. Not a fan of the SP stuff. If this is a paint grade interior project, might look at Marvin Integrity stuff. IMO SP is a lower end builders grade product. I am in the Los Angeles area for what is is worth

I'll let you know in a couple of weeks I just purchased SP for the front (historic view) of my home. Candidly - if they fail 5 years earlier on average, I make out significantly better from an expense standpoint. The first quote I had from Pella and Marvin crested $40K (not a lot from some perspective, enough to make me reconsider life) I shopped and researched and settled on SP - backed by a 20 year warranty for any wood rot on their clad window and backed by a very reputable and financially strong local dealer. I finally through caution to the wind and went with builder grade rear facing windows and could not be happier - they are architecturally consistent and backed by a so so warranty - at the price installed ($4000 for 11 windows) I am thrilled with the cost benefit ratio. The SP are significantly more - but by mixing the two brands I saved $30K and can do it all again in 15 years if need be. Good luck sounds like a fun project.

Hey. It’s me again! I just thought a round-up/semi-conclusion to this thread would be nice for anyone else struggling to make this same decision. Our house will be finished in another month. I went with all 366 windows. The dealer and the builder thought I was crazy for ever questioning it, FWIW. Here’s my takeaway: The visible light transmission reduction is noticeable. It’s not terrible but it is a slight bummer. The solar heat gain coefficient is no joke. I stood in front of the giant south facing window on a cold sunny day in black leggings and never warmed up. My black leggings were cool to the touch. A dog looking for a warm spot would be very disappointed with 366 windows. That said, I’m assuming it will do a good job of keeping the heat out in the summer. I just wanted to chime in and affirm that these ARE noticeable things. They are real trade offs. The jury is still out for me as to whether I made the right choice. But I’m certain my furniture and floors will be happy with the 366.

On the recommendation of our architect and builder we went with Sierra Pacific Aluminum clad Aspen Casement 2.0 Windows and are in Colorado at 7500'. We do have a few issues, loose aluminum cladding, some inside corners that were not mitered, some warped inside trim pieces, One set of three windows that are mulled together arrived with a really bad scratch. and the only solution, because of the location, is to dab a little paint on the exposed aluminum. If it was at eye level it would have to be replaced but it is up high and not visible to the naked eye so that will be okay with us. The service manager came out and is having everything fixed. My advice is, regardless of what windows you go with, try to meet the service manager for your area ahead of time. We met the SP service manager at the showroom more than a year ago when we were mulling over the windows and he ended up being the same person who came out to go over our concerns so we had a connection. There was one thing we didn't like that was by design, something we missed. The exterior trim for the Aspen Casement 2.0 Windows is assembled using metal screws that will be visible upon finish. The screws are bright silver and don't match the aluminum color. We are going for a modern look so weren't planning to have trim around the windows. About the only thing we can do is go around and dab a bit of paint on the top of each screw which we would only do on the windows that are at eye level. He said no one had ever brought that issue to his attention so maybe it is just us. Other things we didn't realize about the SP windows Aspen casement 2.0 version is that the inside trim pieces are not nailed in. They are held in by something called a rib. This is also by design to cover up hardware and also make it easy to service the window if needed. Only time will tell if this works out. He offered to nail in all the pieces. The windows themselves look great and all came at the exact correct size and had good labels for the installers to figure out where each window should go. Here is something though I still haven't figured out. We looked at the Cardinal Glass website to help us pick which type of glass to use. We also brought out samples and placed them around the house. We went with the Low e 272 which has a Visible Light Transmittance of 72% (we thought the e366 might make it too dark and unable to grow plants) and a Solar Heat Gain coefficient (SHGC) of .41 and a U factor of .30 (without argon). Yet, the VT range for our windows is 48% - 65%, the SHGC ranges from .28 to .31 and the U Factors range from .29 to .32. So there must be some program that considers exposure and a variety of factors to come up with the individual characteristics for each window. So, even though we thought we would be getting 72% of visible light we are in the range of 48% to 65%. There is still a lot of light because we have a lot of windows. I like to grow houseplants so only time will tell if plants will grow. Yes, window selection is very complicated. So that's part of our story with Sierra Pacific, again, only time will tell. We still have a ways to go, the inside windows need to be stained and none of the finish hardware or screens have been delivered as that is one of the last things that will happen. Sierra Pacific does something they call Lock and Slide where they come out and install the finish hardware, screens and adjust any windows that might be difficult to open and close. Hope this helps.