Torsens are excellent for roadracing, but I would rather have a locker for drag or sledpulling. Torsens still let one tire spin faster than the other, but it applies more torque to the loose tire than an open rear does.
Our G80's are actually pretty durable IF YOU DON'T do burnouts. If you like burnouts, it will break. Casper's G80 was in new condition after over 500 passes, I expected it to be showing wear, but no, so we put it back in when we stuck the 3.42's in. If you have a 5-sp Allison, you might consider the 3.42's when you go inside the axles. It ends up with similiar freeway RPM as the 6-sp, and didn't hurt the ET's.