I've had floating stools before and I've heard all it means is maybe you had more fat in the bowel movement is all. Also it could mean you are getting enough fiber.
Floating or sinking... it really doesn't matter. Whatever you eat decides your stool. There are "experts" out there that say that sinking is good because of the amount of fiber, others say floating is good because its more fat... who knows.... as long as your not constipated or go 5+ a day... and not have odd colored stools to go along with bleeding... then your fine