I quite like mine, but I haven't done any work work on it. No typing or anything. I've read a couple of books on it, I've read some manga (perfect match for the monochrome screen), and I've taken some notes on some papers that I'm working through. I'm impressed with the battery, and I've been using it every single day since I got it. Mindblowing? No. Just a nice reading experience. Perfect if you want something larger form-factor than the kindle with more apps to side-load, if that's your thing.

As for the UI, etc, it's just Android with a non-standard launcher. They didn't even write the launcher, it's a launcher you can get off the app store. It's pretty vanilla except for the gestures for back/home. Whether or not this bothers you is probably a function of how much you like or dislike a pretty vanilla Android experience.