RV bedding is a full sized mattress. It is not a thin "want-ta-be". You will find it to be comfortable. Sleeping on it is just like being at home. The RV mattress has springs and a good thick topping on it.
For those who have sleeping problems, you can get one to meet your needs. You can even get a memory foam top. They come in any size to fit any bed you want to have one on.
Some travel trailers have bunk beds in them.
The one we used to have had some of the hardest RV mattresses on them.
No one was comfortable.
You can change any RV bedding out to whatever you want.
One of the best things we did was put a mattress cover over the tops of the beds.
This protects the mattress from dirt, snack crumbs (and yes they do get in there some kind of way), rocks, sand and rips. All you have to do is take it off and wash it.
Getting a different bedspread and replacing the new one may be beneficial, also. Put the new one up and get one that can be to your liking and decorating taste.
Also, you can get a foam topper for them. That gives a little comfort. Ours liked to just put their sleeping bags on the bed and sleep inside them.
No complaints from me. Just toss it in the washer and dryer and that's it. No climbing across the beds or fighting with the sheets in those tight corners.
Most of the time you can find a replacement mattress in your hometown. Some are very expensive. Be sure you get what you want the first time, as most places don't take them back once you have slept on it.
I recommend a mattress that is good quality.
A cheap mattress is not going to sleep any better than the one you already have.
You get what you pay for.
Best rest to you and happy camping!! :)