It would all depend on what sound you're going for. Carpet absorbs sound while it bounces off wood. Softer material versus harder material.
Listen to something recently produced by T-Bone Burnett, then listen to any given song off "The Captain and the Kid" by Elton John. There is a different "texture" to the sounds. The T-Bone stuff just sounds softer somehow, while that John album has a "tinny" sound.