I just replaced a set of 5160s ( only lasted 30k miles of pure pavement) with a set of Carli Fox 2.0s. I've only driven about 300 miles. First impression: very soft. they definitely do a good job of keeping the springs tame. but i think the weight of these behemoths really put a hurting on these smaller 2.0 shocks.
The 5160's experienced no leaks or sign of failure but when i broke the upper nuts loose - they sank all the way down :-(.
I think its been mentioned on this board before - these truck would really benefit from a 2.5 shock, IMO. I just could'n't justify spending $2500 on a set after seeing the failures of the 5160s. If these Fox shocks last a bit longer, I'll probably consider upgrading. Although I don't off-road my truck I spend a lot of time driving in pot-hole ridden roads.