The 900 had a removable battery with a access door to get at it. The 950 does not, it is designed like a longer 650. The 900 came with a Case Logic padded case that was great for travelling and it came with a cover. The 950 comes with neither.

Compared to the 300 and 600, the 900 was a great improvement as it allowed ePub text to be fully justified, got rid of the annoying page number in the right margin, and had a better body design. Plus it came with 3G, though the usefulness of its 3G was limited.

But since the 350 and 650 also allow ePub text to be fully justified and don't have the annoying page number in the right margin, and since the 950 body design is merely a stretched version of the 650, much of the advantage is gone. It does have WiFi and 3G and a longer screen, but to be honest I did not like reading PDFs on my 900 or on my bigger Kindle DXG. PDFs on any eInk reader is a bad experience for me anyway.