As a hardwood floor enthusiast, having been in the hardwood floor business all my life, it is site-finished hands down for me. Aside from the aesthetic knocks I have against prefinished floors (seams you can see and feel with your feet, a funny sheen, no choice on sheen, color fading problems, etc.) the main point I stress with my clients is maintenance. You mention small children and a dog, both of which I have to contend with on my own floors. Any hardwood floor you choose will eventually show signs of wear. With the proper finishes on a site finished floor, restoring your floors to new is very feasible. With a factory finished floor, it is virtually impossible. With the current cost of unfinished red and white oak in standard widths of 2 1/4" and 3 1/4" at extremely low prices, we have been finding that site finished floors can actually be less costly than even median factory finished floors. The difference in material price easily offsets the cost of sanding and finishing. Of course, any homeowner making this decision must consider the possible issues of dust, fumes, and time off the floors. It is imperative to find a top-notch floor finisher who works primarily or exclusively in occupied homes. You need a finisher who can keep dust to an absolute minimum (which is possible) and who uses high-end water based urethanes such as Bona, Glitsa or Basic Coatings. Each of these companies makes a commercial grade water based urethane that will be prefect for your traffic needs. They are also very low in VOC's and some are green guard certified. The best reason to use them, though, is that 5, 8, 10 or more years from now when you see a traffic pattern becoming visible, a good floor finisher can use the same finish to "re-coat" just those areas showing wear. It is possible to blend these newly recoated areas into the surrounding areas without moving all your furniture. This is typically very affordable and takes only a few hours to complete and dry. In this way you are able to indefinitely maintain your floors making it possible to avoid ever sanding them back to the wood. Unfortunately, with prefinished floors, once they wear out, all you can do is to sand them back to the wood and do exactly this process. To make matters worse, most of them now come with aluminum oxide finishes which make this refinishing very difficult. I say, why install a floor trying to avoid refinishing when refinishing will eventually be the only way to make them look good again? Get it right from the start, use the best finishes out there, the right finisher and then maintain your floors. You will have floors you love for life.

I think the misinformation was about screening and recoating a site finished and doing a board replacement. On site finished if you have a problem its much harder to do a single board replacement and have it blend. Most times you would have to resand the entrire floor to make it look good. With factory fiished a single board could be replaced without resanding adjoining areas. Either could be screened and recoated without sanding. Comments about factory finishes scratching are sometimes due to the fact that with multi coat products the almunium oxide is left off the top coat. It tends to look milky and the idea is to make the top coat easy to repair when scratches occur so its often pure urethane with the AO below the top coat.

In theory the site-finished hardwood will have a slight edge on "water resistance" than factory finished. As Handy Mac points out, the finish will coat the entire floor in a single SHEET of finish. Now...that isn't to say it will be SUPER water resistant. It won't be. Most wood will have issues with large amounts of water allowed to sit on the floor. But the worry you have - water getting between the planks - is greatly reduced with a site-finish...again it is a large SHEET of finish that spans the boards = a thin layer of plastic = a little bit more water resistant than factory finished. Again...these numbers and 'time frames' are very similar. But there *should be a slight advantage for the site finished. That's why we require our cork floors in kitchens be site finished after installation - the polyurethane spans the joints making the floor resistant to surface spills (many hours of protection because cork itself doesn't care...but the fibre board in the middle does).

Ok...first things first. Janka hardness ratings only apply to solid hardwood. Engineered planks do not work with Janka because the plied layers underneath are often 'soft woods'. Considering Janka measures how much force it takes to imbed a metal ball into the wood, it isn't possible to offer Janka scores for engineered. They just don't compute. The next thing I'm going to point out is the oddity of trying to match the ENTIRE HOUSE to a single room of existing hardwood. You have a small amount of hardwood that is dictating the rest of the house. It's not impossible but it is HIGHLY unusual. In other words, you are trying to put down more than a thousand square feet of flooring by trying to match 150 - 250sf of dining room (I don't know the size of your dining room so I'm only guessing here). That's a little like putting the cart before the horse. Usually we see this the other way around. Usually we have a house full of hardwood (big amount) but the bedrooms have carpet (small amount). The homeowners then agonize over getting a match for the smaller area. That is normal. As for your price range that you are looking at, they are too low and a little thin. The gold standard is 3/4" thickness (solid or engineered). An engineered product with 3mm or more of wear layer is the base level. The thicker the wear layer the more times a floor can be refinished. The Gold standard is 6mm wear layer (usually in the $10/sf range). If you are having a hard time finding floors that you like, you might want to think about replacing the dining room at the same time. This takes away all the pressure to work with low-grade hardwoods just to get a match to a small amount of hardwood. Solid or engineered should be more than what you are looking at for price. Prefinished wood flooring should be in the $7/sf just to start and they go up from there.