i had a VW r32 for 2 years and it had the haldex system. it was normally 100/0, f/r. under slip, the haldex would move to 50/50.
however, it was possible to buy (expensive) modules to make the haldex act more aggresively, making it feel more like a rwd car.
however, it was mechanically possible to have the torque split 0/100, f/r, with the right module.
haldex is strange though. the module that controls torque distribution is not electronic....it's hydro-mechanic. it definitely was strange. but it's the same set up that the Audi TT uses.....although i'm not sure if the new-gen TT uses haldex. in all, haldex is different from torsen or any other AWD system. but you can't tell the differences between the type of AWD unless you are pushing the car really hard.
would the MS3 be "better" with awd? eh, i think it would weigh too much and would lose some of its nimbleness. that my .02.