I really like the multi-funtion of the "Lego" type blocks. If the site is level, but a bit muddy or wet, I use them under the stabilizers. On an unlevel site I use them under the tire and then use the extras so that the stabilizers don't have to be extended as far. On a site that is unlevel front to back they help prevent needing to crank up the front jack to the max. Stored in their carry case they are farily light and easy to fit into storage places. I just ordered a second set to use with the twin axles on our upcoming 21.
Eric (and Mary who is in no way responsible for anything stupid I post)