Been using mine for nearly a week now, and no freezes or crashes (It once took a -very- long time to open a PDF, which I eventually aborted by pressing the Home key).
This is with the original firmware (1.0.0.something). I just upgraded to 1.0.2.10280, so we'll see how it goes for the second week
Usage has mostly been reading an ePub (up to 2 hours at a single sitting), but I've also opened various other books (71 installed on the device in 25 categories, mostly ePub but also a few PDFs). I usually use the hardware buttons to change pages as I find that much easier to use single-handed than the swipe.
WiFi has been both 'off' and in 'standby' while reading; I've done a tiny bit of web-surfing on it trying to access online book stores.
I use Linux and Calibre to transfer books to the T1.
Cheers,
- Micha.