gloryb,
Sounds like you've read my previous posts on this subject. I've been full-timing in my TT since the end of last July. After 10 months of sleeping on my Denver Mattress
every night, I can honestly say "I love it"! As I've posted before, I bought a 3" memory foam topper from Target. I tried it on top of the mattress for a week, and didn't like the slow response time - especially the slow "spring-back" time. Read someone else's post on here about putting the topper
underneath the mattress, so I gave that a try. What a difference! Since my Denver Mattress is
not a pillow top, I added an old 1" corrugated foam rubber pad on top of the mattress. I then put a regular quilted mattress pad over the whole combo. That combination gives me a fabulous sleep . . . the best I've ever had. I did spin the mattress 180* in January, since it was starting to dip a little where I sleep. I'll flip it over in another couple of months - just like you would your mattress at home.
For those of you who've said you feel like you're sleeping on the plywood base, I ask you to consider putting the memory foam topper
between the mattress and the plywood. That acts just like a box spring, and eliminates the response-time and temperature issues others have disliked about memory foam. It's worked for me every night for the past 10 months!