ahhh. so basically. from a standard diff to an atb diff. i would be gaining booger all, as if one wheel was spinning like a nutcase you'd loose all power to the wheels (same kinda thing as it being lifted off the floor?
atm sadly the capri tends to cock a rear leg still in chicanes (sp?) and just spin the inside wheel up. dependin on how aggressive your right foot is .

so ATB diff basically works well (when your launching before wheelspin) and good at tending not to want to lock when going too hard on the throttle round a corner (if you cock a wheel off the floor)

whereas the plated diff (after being set up), will always send power to the wheel on the ground, and (with enough right foot action) will lock both rears to power around a corner thus keeping the wheel on the floor with plenty of power to use (or break free in a drifting circumstance)?

ATB sounds like a waste of money so far lol