We've had a solid walnut floor in our hall since we moved into our house 6 years ago. It's still in good nick, but (and i don't know if thuis is different with the semi-solids) it was quite knotty, and the better half popped a small knot out with a high heel once, so there's a small little hole near the front door and a new rule about high heels in the house....
in terms of maintenance, a quick sweep and take up the pile with a dustpan or hoover keeps them looking good.