i dunno mael, re: Vees the annoyance is when the rim is just off-true, i cant adjust the v calipers such that the pads almost touch the rim - there's always some rub. Why i want to do that is so i can get braking power with a quick and short depression of the levers. I thought disc would solve that problem? That and stopping power over wet areas.

Good insight provided OregonXC, after some research on avid's tech manuals i think i know the difference b/w the 5s and the 7s now.