I purchased the Ultima Plush, extra deep rv mattress cover from AB Lifestyles. They have all rv sizes. It fits well, and is comfortable. We packed away the bedspread that came with the coach, and added a down comforter with a pretty cover that matches the coach colors. We just flip the bottom up before putting in the slides. Judy D
We sold our mattresses shortly after delivery as the standard ones are pretty bad. Replaced with latex mattresses from Latex Mattress - 100% Organic & Natural Latex Mattresses - Sleep EZ. They cut it to size for us and everything. Came vacuum sealed in a box, took it out on top of the bed platform, cut the seal and pulled it out. Then put the cover on.
A couple great things about it, there is zero and I mean absolutely zero smell. No VOCs. No funny chemical smells. Nothing. U can bury your face in it the second it comes out of the bag, Secondly, the mattress cover comes off and and easily washable. Third, you can rearrange the layers to achieve the softness or firmness you want and split the layers vertically so DW and DH have their own preferences. Same concept as sleep number but more work.
Biggest drawback is that it’s not light, but not incredibly heavy either. Then again, I’m still relatively young.
We use a king mattress pad and have replaced the comforter with something nicer in our previous coach (2014 DS) as it was really cheap. The current comforter, OEM, isn't too bad. The one I really liked, was the one that came with our 205 Monaco Diplomat. It was a heavy comforter, form fitted, and had two flaps that you tucked the pillows under, so it looked like it had pillow covers.
We took OEM one, put in bag and stored at home. Got something which color coordinates from Ross, or Marshals, it works fine. We did however get the sleep number mattress and we love that. Just remember to let the air out before you travel. We also got the Sleep Number "Warming Layer", dual controls, and it works very good to excellent. I have not tried it higher than 2, and it gets bed quite warm, and I have to turn it off. I keep the controls and cords in the nightstands when traveling, and tuck the cord which attaches to the layer tucked under the mattress, it never gets in way of slide going out/in. We have talked about a comforter from "Hotel Collections" since they are very well made and thick with lots of down filler. With the warming layer, we have not needed it, but did add a light blanket under the bedspread to add a little more covers, that seems to work when outside is cold. We keep thermostat set at 65 at night.