We are in the process of deciding on bamboo flooring for our kitchen/living room/hallways. We have been advised to float it over the vinyl and thin tile on our concrete foundation as the foundation isn't completely level. We have been advised against using a "click" system due to unreliability. Any comments? Also, this is the first I've read about this flooring scratching easily... how much of an issue is the scratching? We're planning on a medium carbonized horizontal style in what are high-traffic areas.

IMO, bamboo is of average durability, so plan on dents in high traffic areas. Also, as it has very little texture to the grain (similar to maple), flaws tend to show more readily. As Ken knows, I'm not a fan.

carbonized is softer than non-carbonized. Bamboo is compressed and anti-dent, not dent proof.
all flooring products scratch; the difference being "how visible" or how reflective are the scratches.
Nothing wrong with bamboo. Good floor and unique in appearance.