I think sly is referring to the difference between a floating trem and a non-floating (fixed?) trem. Floating trems can bend a note up as well as down. Personally I love
my floating trem and wouldn't swap if for a fixed type. What's wrong with it? Is it that you're used to resting your palm on the bridge and end up distuning it? It's not that hard a habit to get out of you know.