I know too much bare floors, of any kind, I think, is not good for them. When we first got Arrow, we lived in a house that was entirely ceramic tile. He was going to handling classes, we planned to show him. But slipping and sliding, even as a puppy, on all that tile effected his gait. His hind feet actually turned out and he was walking so goofy, he couldn't be shown. Then we moved when he was about 8 months old. This house has carpet everywhere except the bathrooms, kitchen and the laundry room. Within a couple months of no tile, his gait had completely corrected itself. (Of course by then our daughter, who was going to show him, had turned 16, gotten her drivers license, a car and her first job. So she was no longer interested in showing him.) But the carpet was soooo much better for him!
Also, update on the flooring question for our family room: We had a carpet guy come out and he was honest with us (that's a surprise, huh?). He said he thought if we had the carpeting professionally cleaned (we have a Hoover steam-cleaner we'd been using), he thought we'd see a big difference. He said he didn't think the carpet was as "dead" as I thought. So we had the whole house professionally cleaned (with the truck-mounted thing, pretreat and all) and we're really pleased! Now, after seeing [MENTION=530]LisaRN[/MENTION]'s lovely "wood look" floors, we may go that route later on. But right now, we're glad we just had everything cleaned.