With a 26footer like mine I see them as something I don't need,the cost and the extra weight is something that doesn't appeal to me.Also one more thing that I will not have to worry about going wrong.
I have seen in the places that I camp the people with jacks have to put down a block so they won't sink,that just seems to be to much work.
I carry
These,they have never sunk are simple to use and store nicely. I tried the Lego type blocks,problem with them is you have to carry a lot of them as noted and if you don't get it right the first time you have to drive off then re stack them,also to much work.
I have have found that the ramps are a one and done deal,works for me but may not be what some want.