We had two studios at Wilderness lodge this past summer. I slept on the sofa bed in one unit, and my ds did in the other unit. I had no complaints and neither did ds. It was very comfortable, or maybe we were just extra tired.
The 1 bedroom we were in had a new sofa bed - tag said june 2006. We were there in October. These are the ones without bars. I think they are quite comfortable if not a little too firm.