Kindle 2. Haven't tried PDFs. I got the international version which comes with its own troubles (less and costlier books, no blogs, etc), but I have been managing to hack around so far.

Good news, its quite fast here in Mumbai and I am having fun. I mostly work on the go at coffee shops and I have always liked referencing a book more than the internet, and with kindle now i have my library on the go.

PDFs on the Kindle 2 are effectively unusable in 99% of cases. There's no zoom function, so unless you break out a magnifying lens, you won't be able to read a damn thing on most PDFs. Quite sad, as I was looking forward to the update :(