Hi.
The Wavetrac is a torque biassing diff,similar in concept to the Quaife,which I've got on my car.
The Wavetrac is said to be less aggressive in action than the Quaife,but both are extremely good at finding traction on less than perfect surfaces,and certainly cornering hard on a wet road,you'll really notice these things at work.
There is a definite tendency to pull you into a corner,and also for the level of steering input required to change rapidly,so I'd say you do have to adapt and accept a different feel to what you're used to.
I've also noticed that it will fight with the TC on difficult surfaces,leading to pretty gross understeer,and I expect that has a lot to do with the way that Audi's TC works,and so I leave it switched off.
http://www.wavetrac.net/technical.htm
http://www.focusst.org/forum/focus-...eview-wavetrac-limited-slip-differential.html
Differences are pretty small overall,but the Wavetrac may be cheaper.....against that is Quaife's lifetime guarantee,and the fact that lots of rallycrossers use or abuse Quaife's products every weekend,and they don't break.