The phone design is nice. 4.0" may be my new sweet spot. The external speakers are amazing. When you use the DTS boost, it's super loud. The G2X appeared snappy, and then I loaded all of my 150+ apps, and it was only marginally faster than my MyTouch 4G (MT4G). The pure Google experience is nice, but even still, I kind of like Sense. I had to do too much customization to get it to act like certain aspects of the Sense UI, but it's possible. The camera is passable, but not top notch as the specs lead you to believe. I took some high res pics and compared them to my MT4G, and they weren't that much better, if at all.
Mine was quite buggy. You can read about many of them on the boards here as people are quite vocal about them. Some are inexcusable like not being able to delete the default sig. Of all the problems that exist in early releases, this is just one of those that has no business being an issue in all honesty. I also had some issues with having to manually perform pairing over and over. It would delete my devices. Wi-Fi would disconnect as well.
I really wanted to like this phone and make sure it was my primary device for the next quarter at least, but this turned out to be the device I returned faster than my iPhone when I had it (3 weeks for that). Back on the MT4G, and I'm not realizing a lot of advantages the G2X had over the MT4G.