RV 5th wheel ,Hid a beds are the pits, haven't found anything to replace ours with either we removed the eating booth/table out of ours and replaced it with 2 recliners, use TV trays to eat on. The booth was not compatible with our age, sliding in and out of it was nuts. But the hid a bed is the next thing I would love to replace, I was thinking about on of the old style ones that the back and seat fold out to make the bed?? our over head buck is not an option for an one but small kids. that we use for storage . Happy camping

We have a small (as in tiny) teardrop trailer. It came with 4" foam mattresses for sleeping on. We replaced it with an air mattress and this works great for us. We sleep on a waterbed at home and this is very similar. The only problem is if the weather gets very cool then the mattress gets cool as well.

We took the couch out of our 5th wheel (we had to cut the back to get it out of the coach) and replaced it with two wall away recliners (smaller size) and a queen size air mattress (just in case) We bring in two of our folding camp chairs if we need more seating space inside. I certainly agreed with your opinion of the hide a bed. We are pretty satisfied with our new arrangement.

We remove the uncomfortable sofa and replaced it with a solid Oak desk we found on Craig's List. the desk makes the perfect sewing "room" during our winter migration. We use two office chairs to sit on.

DH bought a big brand new 5th wheel a few years ago to try out RVing for the family vacations. He didn't think to check out the sleeping compartments and no one would sleep on them after the first night, not even him. We parked it in a motel parking lot at night for the rest of the trip. LOL He traded it in for a boat. He hasn't mentioned wanting to try again.

Not so uncomfortable for these two
 

We spend about 6 months in our fifth wheel and the couch was just useless...so we purposed it. We have two big dogs who occupied the entire floor. We had to jump over puppy puddles (sprawled out dogs) any time we needed to move. We took off the back pillows and covered the couch with a comforter. Our two furbabies are now out of the way and can look out the windows. We haven't had guests overnight yet, but the hide-a-bed should still be useful as it is well protected and we give visitors the chairs and sit at the dining table.

If you have room and your couch isn't over the water tank I agree with the lady that said put two or 1 recliner chairs if possible, you can always nap in the chair.
We have a fifth wheel and I bought a new mattress for our bed I Googled RV mattresses. I would have loved to have the chairs.

Try using a light thin board between the mattress and the springs and bars. That keeps you from feeling the iron supports. Also, the idea of a memory foam top sounds good. We had a fouton mattress and it was very comfortable.

We went searching for camp pads (our sienna is our grandchildren carrier and our camper). The backpack ones just weren't enough for our aging bodies! One store told us they didn't have what we wanted, but to go to a certain upholstery store and they would have what we wanted. We laid down on these recommended pads (they were referred tio as "memory foam", aghast at their cost ($100 each!). But they were surprisingly comfortable, and we need that comfort and these pads fit into our car perfectly and they feel sooo good. I had to put covers on them (used fabrics I thought were really ugly and that were a bit heavier). The expense was great, but when we have the family here for special occasions, or just grandkids visiting, these pads are great extra beds! So in the long run they were a very good purchase. Sorry, I don't remember the technical name (maybe "memory foam" is the only name???)! But the store personel and the price can steer you into the right direction.

[Have to add, we live in snow country and all but one of our kids and families live south, so they are always eager to come here for Christmas so the kids can play in the snow. Our max has been 12 of us in our one bedroom apartment! They all used to camp with us when they were kids and they filter into their spaces, and the adults get the sofa bed, the other couch and the pads! The kids bring their quilts and we use other, old store bought quilts for their padding.]

My brother and his wife needed to replace their couch in their camper...what they did was ordered a piece of a sectional couch... one end has a arm rest and the other does not... it is so cozy.. can't sleep on it.. but... no one wants to sleep on the original one anyways.. lol