We have 3 memory foam mattresses - one in the house, 1 in the 5er, and 1 in the MH - wouldn't have anything else - I've had 2 lower back surgeries, could NOT get a good night's sleep on a conventional, good quality mattress - but do GREAT with the foam. Learned quickly that you need at least 4 inches thick for best results.
One sorta side issue I might comment on - the foam SLEEPS well - but is totally resistant to "bounce" or similar motion - so. if you plan any mattress activities involving "bounce" or motion for best effect....
John Day....|'88 Winnebago Super Chief 27ft. Class A
Eastern .....|'88 KIT model 240 24 ft. 5er
Oregon ......|'02 Dodge/Cummins 2500 Quad Cab