Thanks for the response.  I was just reading the reviews on Amazon and they are, for the most part, favorable.  I tend to camp by myself (with at least 400 pounds of dog) so leveling side to side means I back up, get out, check for level or that the blocks didn't slip off one or both tires, fiddle around trying to get them to stay and then try again.  It is my least favorite parts about setting up camp and as smart as the hounds are, they've not figured out I need them to give a yelp when the air bubble is in the center.