I'm a huge fan of all things Camco, but I like the Hopkins for one simple reason. They have a straight edge on the bottom, and this simplifies lining up the level with the trailer frame. These are disposable items...especially the one on the front of the trailer...because a stone can blow them out in a second. But I keep a couple spares in the camper, and they are very easy to replace without having to level the camper first.
https://smile.amazon.com/Hopkins-85...UTF8&qid=1499102485&sr=8-1&keywords=rv+levels
I don't just rely on the sticky tape...I also screw them to the frame.
As for carpenter's levels, they are great, and far more precise, but with a PUP, leveling the trailer typically comes well before the opportunity to throw a level on an inside counter. Plus, the Hopkins levels are more than accurate enough for sink drains, fried eggs on the stove, etc. I rough in side-to-side leveling on my single-axle PUP with my handy Camco wedge.
https://smile.amazon.com/Camco-4457...=1499103099&sr=8-6&keywords=camco+rv+leveling My wife monitors side-to-side leveling as I pull the PUP up the wedge, then she throws a wheel chock in to hold things. When I unhitch, my wife monitors the front-to-rear level...on the curb side of the PUP frame as I crank the tongue jack. Once we're roughed in, I use the stabilizer jacks to tweak things a tiny bit, and we're dead center on the bubbles in both directions. (Stabilizer jacks aren't meant for leveling, but they can handle an inch or two of lift with no harm done. I always start with the lowest corner, jack until just beyond level, then snug up the other three corners without throwing the PUP out of level. In my 4th season with no problems.)
One other tip for leveling on more "extreme" slopes. Dig a hole on the uphill side for the tire(s) to drop into. Very effective, and saves a big first step on the stairs. We camp near a lake frequently, and the side slopes can be pretty severe. I use the hole and wedge techniques there.
