I bought this to use as my "every night" mattress on a platform/slat bed. It's super comfortable and I'm really happy with it so far! I put a feather bed on top, just because I had it laying around, but I don't think it really needs it. After sleeping on this for 2 weeks, my boyfriend's mattress (which was perfectly fine before!) is suddenly uncomfortable in comparison. Maybe I'll move the feather bed to his house!
I live in an Airstream and wanted to replace the smaller-than-twin beds with something larger. I was concerned that the relative thinness of the mattress would be an issue but it's not at all. I am using a roll of bed slats from Ikea to span the gap between the 2 twin bed platforms, with this mattress on top, and I can't feel the slats and never feel like I'm even close to sinking down far enough to do so.
There was no smell or shape issue when I received the mattress. It comes compressed and rolled. I cut open the plastic, unrolled the mattress, and it was ready to go. It takes up most of my bedroom and I find myself folding it in half in order to change the sheets, so yes it does fold easily. I look forward to being able to shove this into the back of my small car when I move, instead of being at the mercy of the "friend with a truck."