Both of my rigs have had Power gear hydraulic levelers. And I like em.
#1, a '99 pace arrow, had 4 point with external springs. It wore out the pump, I found a brand new replacement on ebay.
#2, the 08 knight, has a 3 point system with internal retract springs.
Both of these system are BEEFY. I read posts on here about people not wanting to lift their tires off the ground, than I look at rigs in campgrounds and see these tiny little pistons... nope, I wouldn't either.
The powergear pistons are BIG. The front single on the knight is four inches in diameter!. It would lift the space shuttle.
Those ones with the tiny 1" pistons and 2 little retract springs? them are the cheap ones and I wouldn't trust them to level a popup!