Lakeman, I have done 3,000 miles on a set of ME Z3s (regular, not race), including 240 miles on the track with those tires.
They stick much better than OE, especially in the rain.
The MEZ3 has a significantly rounder profile than OE, so you keep much more of the contact patch at extreme lean angles.
For what it's worth, I recommend them without reservation as a serious step up from OE.
Right now, for other reasons, I'm on a tx25 200 rear with the ME Z3 front. It's an even better combination for me because you get the great front stickiness in dry and rain, plus the awesome off-the-line acceleration of the 200 rear, and the tx rear slides a little more readily (better rider feedback) in corners than the ME Z3 did although much less than the OE Slipstone tire which was like riding on margarine.
Hope that helps your decision.