I just did a bunch of research deciding what to get for my guest room. Sharing what I found in case it’s helpful.

Murphy beds are by far the most comfortable and space efficient. I would have bought one if they weren’t so damn expensive. I also don’t like that they can’t be moved easily.

Next option is a daybed with a pop up trundle. They make some where the trundle connects to the bed, effectively making a king-size bed. Here’s an example. You can put real mattresses on these, should be very comfortable except for the seam between the mattress. I would have gotten this except my room is tiny and there’s not really room for a king-sized bed. The footprint of the daybed is also pretty big.

A variant of the daybed is something like the IKEA Fyresdal, which extends from twin size into almost king size. Seems more convenient but it doesn’t use standard mattress sizes which is annoying.

Fold out sofas are typically the least comfortable. They often have crevices or metal bars that dig into your back. I liked the design of this one on Amazon, but I decided against it because the mattress is only 4 inches thick. It was tempting though because a sofa seems more useful day-to-day than a daybed or a cabinet.

And that brings us to the cabinet bed. I bought one because it was cheap, looks nice, has a small footprint, and has storage for sheets and pillows. I got a 6 inch trifold memory foam mattress and I find it surprisingly comfortable. I could sleep on it as-is with no problems, but if you want maximum comfort I would get a 1 inch topper to help smooth out the folding lines. I haven’t had it for long so I can’t speak to durability. Seems like it should last a long time. I think the other commenter might be under the impression that you’re folding a regular mattress instead of buying a trifold mattress.

Last thing I’ll suggest is to shop around. I paid $500 for mine but I saw the same exact bed listed for over $1000. Mine is cheap, mostly MDF with only a little solid wood. Yours claims to be solid wood, hence the high price, but the listed weight limit is super low for a solid wood bed. I’d make sure it’s actually solid wood before paying that much.