I’ve been MORE than happy with the 5100 series on my ’95 F250, 4″ lift, ~7000# truck, ~2500# camper load, Highway performance is stable and comfortable, but off road, gravel, washboard etc, they TOTALLY OWN the rough country or (god forbid) the Rancho 9000 that I’ve tried in the past. The 5100’s did take a minute to break in, which was a change from the other brands, but wow, night and day change of ride comfort and control off road. Not sure how long they will last, but I have 10K miles on them, and if I had to replace them tomorrow, I’d buy them again. If you primarily drive on the freeway, don’t spend the money, buy the Monroe, or whatever. BUT, driving 10 thousand pounds of truck/camper/load at 60mph from pavement to washboard gravel, to off-road conditions, I don’t think you’ll be disappointed with the 5100’s.