I love my Summit. I have a 2000kv brushless in mine and I have it tuned down to Just fast enough. I'm not running it at 100% maybe 80% The locking Diff is the weak point. I had to shim my spider gears and use Ceramic bearings in the Diff. I broke 2 diffs right after going brushless. Turned it down, and did the mentioned to the diffs and haven't broken one since. And its plenty fast. Even stock its fast enough to be a real blast. Not everything is about getting the most speed out of something. Sometimes its about balance.