We're getting ready to finish our floor and would like some professional oppinions on wether to go with a Satin poly finish or a Semi-gloss. We prefer the look of the Semi-gloss but wonder how it will hold up and show wear compared to satin. We are a family of 4 - 2 older sons soon to be out of the house and one dog.
Also, 2 coats or 3? What is the norm?

the higher the sheen, the more imperfections are reflected. WIth a large family and dog, the lower the sheen, the wiser you would be, in my opinion.

Most finishing systems are three coats. Depends on the product and brand. Not all floor finishes are the same. A satin will hide scratches better but a semi-gloss does look good. It is my fav as well. Personally, if you like the slightly higher sheen, I'd go with that and plan on recoating a little sooner.

I WOULD GO WITH 3 COATS OF SEMI-GLOSS FOR A TIDY SHINY FINISH OR IF YOU THINK THE KIDS AND DOG WILL BE RUNNING ALL OVER THAT FLOOR WITH TOYS AND WHAT NOT, THEN ID GO WITH SATIN.

I about ready to install a new floor, and it will be a low sheen. I have one large dog and no kids, but with current the high sheen I can see every little imperfection in the floor and it drives me crazy!!