Bought one of these when they were offered last September and I've been quite pleased with it. Wanted a small wifi device for ebooks, music, and web-surfing from the couch, and it's definitely fulfilled all of my needs there. In addition, I really dig the GPS functionality which I've used for turn-by-turn navigation and with an exercise app (Endomondo; highly recommended).
There are of course some things to be aware of if you're purchasing one. As mentioned, this has Android 2.3 Gingerbread and you can fully expect that it will never, ever be updated. Some folks have hacked together ICS ROMs for it, but I believe they're still generally buggy and lacking hardware graphics acceleration. It's also not the speediest device in the world by any stretch of the imagination.
That all being said, it's been very good at everything it does in my experience. I use mine daily--often for really long stretches--and it's just a fun, handy little device. I haven't experienced any excessive crashing, although it does crash from time to time.
The model on offer today is slightly different than the one I bought. Mine is an international version (of somewhat mysterious provenance), which has a mechanical home-button, while the one offered here is the American version, equipped instead with a capacitive home-button.
5" LCD screen (Nice quality. Good and bright when cranked up. Low pixel density, but good color reproduction.)
1GHz Samsung Hummingbird CPU / PowerVR SGX-540 GPU
8GB internal storage, with MicroSD slot supporting up to 32GB more.
Wifi 802.11 b/g/n
MicroUSB connector (Yay!)
Speakers, Front and Rear Cameras (rear has flash), Microphone, GPS, Digital Compass, Radio (only works when headphones are attached).
2500mAH battery - 6+ hours of continual use
It's served me wonderfully for the past 9 months, but it will probably be spending more time on the shelf because I have a Nexus 7 on pre-order. However, if your budget is around $150 and you're looking for what amounts to a nice Android PDA, I can totally recommend it.
If there's anything I haven't covered, feel free to ask.