i'm pondering these as a replacement for my faithfull rhyno xl's. can anyone compare relative durability (as a dh rim for a smooth, middleweight guy)? i typically get a season out of my rear xl's, the fronts last pretty much indefinately - if the dt's are somewhat comparable, i'll probably give them a try. i've heard numerous reports as to the 6.1's cheese-like consistancy, but not much info on the 5.1's.