1000 trouble free miles on my 16 163x3 last season, no braceing and no issues, but I never hit anything hard. The bumpers do fold pretty easy tho. I put ft. and rear aftermarket bumpers on. As far as Cat vs. Doo I didn't get Hi-Marked by my Cat buddies at all here in Colorado, but the one with a 3 incher was a 153. To say the least my Cat buddies were really impressed with my XM.