I was also thinking about the crank kind...they are just a little more
expensive and I though this type would have a smaller footprint. Also,
it seems like they are on a 15-degree-or-so angle which I thought would
make them even sturdier.

But I did have the same thoughts as what you are saying about them
being ratchet-type jacks. I talked with a friend who has a camper and
he has the post kind...I can ask him if those type are truly
incremental.