I got this for my mother, who is wheelchair bound and has Parkinson's disease. She has a lot of hip, knee and back pain. She has been using an adjustable hospital bed at home, and the mattress and gel overlay were awful, no matter what you did to it. We ordered this mattress because it was a very reasonable price. (We got the twin XL.)
Last night was the first night she used it. She slept 8 hours straight, and woke up without any back pain, which hasn't happened in probably 20 years. Her bed is adjustable, so that was a big part of it, as well.
The mattress has a nice softness to it, but it's much denser than I would have thought, which is good. She has difficulty getting in and out of bed, and mattresses that are too soft make it a challenge for her.
I opened the box before I went to work in the morning and laid it out on my bed during all day. It didn't any time at all to assume a normal position. I set it up when I got home from work. We did not notice any odor from the mattress once we took the plastic away from it.
Something I didn't notice in the product description (which I probably just missed) is that the mattress has a removable lining to it. The cover zips off so it can be washed. This is a nice feature. I hope this mattress holds up for a long time, because it's great for my mother!
Update: After using the bed every night for 10 months, it still retains its original shape and density. It's just as comfortable as the first night she used it.