I have ceramic tiles throughout the first floor of my home and my system sounds great. I also have almost nothing on the walls which adds to the rooms reflective qualities. I just played with all my speaker settings until I found a sound I liked. I only moved in last year so I'll decorate the walls sooner or later, which will help.
I'm sure it would sound different with wall to wall carpeting, but I live in Florida and go jetskiing a lot and wanted a floor that was easy to clean. I do have a big floor rug directly in front of my system which I'm sure helps a great deal.
Check out the link in my signature to see pictures of my room.
