Hoolihan- The stock slipper is a cheap soft metal. I got a new one when mine started loosening, and used red loc-tite. Never any problems since then.
jsflagstad- as far as HPI goes with warranties, they are pretty good with them. When mine went, they sent me two by accident. loss on their end. as far as hobbyking esc's go, I don't have experience with those. I think people will usually go with 90amp plus rated speed controls.