I realize that my Happijacs see more arduous use than most of you here on this forum. I use my camper in the Winter at a ski area in Washington State and they do salt the roads here unfortunately.
Many people come up here with their truck campers throughout the season, many different brands of campers and different brands of jacks.
I can say from everything I have seen up here is that the Happijacs will fail in this environment. My friends with their Bigfoot replaced all their HJs prior to this last season due to jack failure, cost them $1300.00 for new jacks. We had to saw off the lower jack leg on another friends Nothern Lite this last winter since the jack seized up and couldn't be retracted even with a hand crank.
Another friend of mine who often full-times here has Atwoods on his Lance and outside of some rust on the outer tubes he hasn't had any jack problems at all.
So from what I have seen and experienced the HJs are prone to failure while the Atwoods and Rieco Titan are not. Just sayin!