We have the IKEA Beddinge too. It has made me prefer a futon over a sofa bed but it's still not great for extended sleeping. The mattress is too firm so it gets painful after a few nights. I like that it's not the soft type of futon mattress that ends up lumpy and awful though. I think with a pillow top mattress pad added under the sheet when making up the Beddinge it would be great- I'm going to try that next time we set it up.

I like the old school sofa beds that had a foam mattress that pulled out a laid on the floor. The new ones with that metal bar are usually all awful. My BIL has one he swore to us is comfy and we wouldn't feel the bar and he was right. Slept on that for a few nights and it was super comfy. Seems if you spend enough money you can get a decent sofa bed.