It supports all type of file formats (including pdf, epub, mobi and cbr which are the ones I use). Has wifi. Is superlight. If you look around it's even cheaper than the kindle. Advantage is that you are able to rotate the screen, which is a feature that is no longer available on the kindle. The system is quite stable, and battery life is ab. 1 month. It even has a social app to connect to facebook if you are into that.
And not to mention... it's superfun and nice to read... easy on the eyes... I love it!