563 is dead on. But also, one of the things suspension will do with a floor tom is give you some "bounce." This is either a pro or a con, depending on what you like. I, for one, like the tom to "give" a little under mystick - it feels natural. Floor toms feel "stiffer." There is a difference in sound, but I don't think it's anything real big.
My philosophy is this: Floor toms are already fickle drums. So I do all I can (like suspension mounting) to make sure that drum will resonate in harmony with my other drums.
Plus, it attaches to my ride stand, so that's 3 less little floor tom legs getting in the way. I hate tons of stands and legs. Bah.