The hardwood stairs are what got really scratched up from my black lab. He really digs in running full speed up and down them. We had to sand the stairs down and refinish them. It didn't really matter how well i kept his nails groomed. Though keeping them trimmed really helps the floors. I tried booties but he chews them right off.
I've heard that walking them on concrete can really dull down the nails and that helps, though i never tried that. I always let him run around in my backyard on the grass.