From a long time usage of hydraulic levelers (HWH). They have performed flawlessy. Once having to clean a dirty connection on a solenoid.
My only complaint, is that mine are messy. constant weepage of hyd. fluid around the fittings in the pump area. and an occasional drip under the rear slide area.
If electric jack were as dependable, I would not complain.
My diesel has the rear radiator. If I had a choice I would go with a side radiator.
I have to contend with keeping it clean from blow by from the engine slobber tube.