Ive never seen a direct drive two speed with a slipper. Only on a set up like the Savage tranny. As long as the gear mesh is set correctly you wont have any problems with the plastic gears handling the power. The diffs are the weakest link in the whole drive train. Im using a BUKU pipe on my TZ because I got it for a very low price. Ive heard good things about the trinity pipe with the TZ though.