Yeah when I was in school and training, they shoved double clutching down your throat and talked about how bad floating was, etc. But in reality it's only bad when the noobs try to do it and grind em until they find em. I already knew how to float when I started school, but my first trainer really helped me perfect it. Then the second trainer flipped when I did it and said I had to double clutch. I did it to appease him. I thought he was full of crap but apparently he played totally by the book on everything.
One time I was laying in bed and he thought I was asleep. I figured I'd catch him floating but nope...double clutched every single gear, every single time. Of course this was also the guy who would, even pulling 45k, start in 4th and rev the piss out of the engine and ride the clutch to get it going. Then max out 4th and skip to 6th and lug the hell out of it.