After reading some of the reviews on the product, i was a bit worried about how accurate some of the description would be. The mattress is firmer than you'd expect (i'd say the medium is about a 7.5 on the 10 scale), and it takes a couple weeks before the mattress feels right. Prior to that, it's even more firm, and doesn't form well to the body.
The heat issue for me has been mostly non-existent, although with the summer months coming on we'll see how it compares to my old inner spring.
The covering apparently has been changed from previous versions, as it's easy to tell which side is up because of the co9lor and detail of the cloth.
The bed is a great deal more comfortable than the inner spring i had, and is well worth the price.... definitely a recommended purchase.