The problem with tracks are if you dont have enough grip (ie using metal tracks) then you just end up sliding around, and all that weight in the system is wasted, if you have too much grip (ie soft rubber) then you put huge loads on your drive system, a tracked robot needs alot of power to turn. I've got a set of stainless tracks that were orignally going on Battleaxe (didn't due to time) these are similar to what 101 used, 101 and ST are probably the only competetive bots that seemed to work well, 101 had rubber pads stuck on the tracks.