The mattresses that came in my 94 Fleetwood are pretty terrible. Yes, there are two twin mattresses instead of one huge queen mattress. They are just stuck together and one big sheet put over the top of them makes the bed into a queen.
They would've been like sleeping on stiff cardboard boxes.
Before we even used the camper the first time, my girlfriend went out and bought a queen size mattress topper. It zipped over both mattresses making it into one big real queen bed. I sleep like a baby on it. I can sleep about anywhere, but she's comfortable and that's important.
One thing I want to mention though. There are a couple of wardrobe cabinets that opened fine with the original height of the mattresses. Now you have to squish the mattress topper down to open either of them. I didn't even realize it would be an issue. For me, not much of a pain, but I wanted to mention it in case you hadn't thought of it and may realize like we did once the topper was bought and put on.