This is a nice simple leather cover that I would recommend. The leather has an attractive texture and the construction and stitching is neat. It does not smell noxiously like the Kindle 2 cover (does have a faint plastic chemical smell, but not that noticeable unless you hold it to your nose).
The biggest improvement comes from the magnets that 1) hold the Kindle to the back cover and 2) keeps cover shut. It doesn't take a lot of force to open, but holds it shut securely enough in normal situations.
I read the other reviews about the weight of the cover, but disagree. The cover itself is actually fairly light weight. I have a hard time imagine it being any lighter unless it's made out of a different material or made smaller. It's basically just leather, thin padding, and a felt-like inner surface plus the magnets and the clasps. While the DX is much heavier than the Kindle 2, most of that weight is from the DX itself and not from the cover.
I like this cover for its simple and understated design. The padding is thin, but thick enough to protect the DX. The felt-like inner surface is soft and won't scratch the screen or backing.