We're using a leveler like that when we have a big delta to make up (which is one spot we visit regularly). For small leveling, we use our ground control jacks, but we'd rather not have the wheels 3" off the ground on one side. We did have to cut the tip of the wedge to get it to fit between our wheels (as suggested in the instructions), but once we did that it seems to work quite well. Easy to use, easy to pack... didn't see much of a problem, other than you need to go slow and move in a controlled manner (more controlled than when aiming for a 2x6 board, anyway).
I think (it's been a while since we used them) we backed off of them to minimize the 'popping' potential and make for a smoother landing on solid ground - versus 'driving off' them as they show in the marketing videos.
-Tina