3 years of Rallycrossing and 3 years of 4" lift w/ 33' MTR's (6 years of real wheeling and Moab) and my CV's AND brakes were still the factory originals. The brakes were adequate for the bigger tires but stopping distances went up a bunch. This wasn't due to the brakes not stopping the wheels (I could lock them up no problem), but rather just getting that extra mass whoa'd down like everyone else is saying. I think driving style has a lot to do with the longevity of both and a little luck on the boots thrown in for good measure.