i have the E rated but i only have 200 miles on mine, no wandering on the road and ride is great, i have tested off road and these things grip like crazy. on a hill climb with lots of small rocks (bigger then gravel) with my generals there would be slipping and i wourl really have to throttle it, these i took it nice and slow, no slipping, it was awesome,
not sure if there is a difference in E and C rated, but one difference i can tell you is that i didnt have a choice of white or black letters, both sides were black and both sides have DOT with date made, thought that was weird too. hope this helps a little, as of right now i reccomend the duratracs and hope i still reccomend them 10k miles from now