I've been running it through it's paces. I'm back on my laptop at the moment.
First and foremost, PDFs look great on it, and navigating through them is very fast on the current version. I understand that the first version (released last year at about this time) had less RAM and chugged on picture-heavy PDFs. As I got this mostly for Role Playing Game books, so I don't have to carry a small library to my game nights, this makes it perfect. It also means that I'll buy three or so PDF (instead of hard copy) books, and make up the cost of the tablet. And not have a book case loaded with more old ragged game books.
I watched a video on the Kindle, tried some Youtube videos, downloaded the Weather Channel app (for free), listened to some music to test the sound quality.
I'll get my 'survival library' loaded on this thing (some books on survival, farming, general mechanical stuff, first aid, etc, and about a hundred fiction txt books from project Gutenberg). The whole library is only about 2 gig.
As I'm not app-crazy, I think I'll be pretty happy with it. I'm not super-keen on the keyboard, so probably won't be doing a ton of typing on it, but it's not like my laptop died or anything.
I ran the battery down from full to about 1/4 in 5 hours of constant use. This sounds like about what's described, maybe a little less, but I was running the wifi pretty much the whole time.
So... yeah... I'm pretty happy with it.