I have the Sony reader. It was a gift so I didn't get to choose whether it was that or the kindle. I really like the design and feel of the Sony. It's easy to read and I've even caught myself trying to turn the page! It is fantastic for travel!!!

The Sony Bookstore does seem to be more limited that Amazon's support for the kindle. The usual best sellers are there, plus a few others and many classics. The prices are too high I feel since you don't actually get a "book". There are some other sites you can use (see http://www.mobileread.com/forums/showthread.php?t=11052 ) some of which are free. You can also store photos and music on it.

The kindle is more expensive initially (about $100 more) but I think many of the books are a better deal. Also, you can download a book from just about anywhere in the US whereas with the Sony reader you have to first download it to your computer. The Sony reader charges off of a USB connection to your PC but an AC adapter is available.

I think I would have gone with the kindle even though I think it's kind of ugly (the Sony is very sleek).