Hello Richard,
I prefer the air mattress when my back goes south. I set it up pretty firm.
That's right, I choose my two figure Wally world mattress over my four
figure Big Name mattress( with built in memory foam).

I have owned dozens of air mattresses in my lifetime and I would strongly
recommend the mattress with the built in air pump.

The only drawback is the height of mattress might cause head room problems
in your Westfalia.

Ken Lewis
http://neksiwel.20m.com/
in statu viae