There were a lot of issues early on that had me a bit hesitant, but after reading several reviews of the latest mk2 model and 2.0 firmware, it appeared to be in a lot better shape, so I ordered one.
Just wanted to pass along how great this handheld is. Most of the joystick complaints were remedied with the rotation of the mk2 model. The screen is great, though viewing angle is a little limited (or that was my initial thought anyways...after 3 days on it I don't see what bothered me about it originally). Occasional freeze or lockup when starting a game or exiting to the menu in certain emulators, but only takes 5 seconds or so to poweroff/on and your back up and running again. Has TV out on a lot of the emulators, though my adaptor hasn't arrived yet.
NES and Atari are good of course. Recent PCEngine is very good. NeoGeo and Sega emulators are super and are worth owning the system for that alone (fullspeed on everything I've thrown at it so far). SNES still has a way to go, but with frameskip set to 1 and overclocking, a lot of the games are playable right now (and it's only getting better with each release). GBA isn't there yet and will take awhile, if at all. I've had some issues with Mame, but I think it's mostly my romset...still working it out...seems to work for most people. Also some cool homebrews and a couple of promising commercial games. Doom, Quake, DukeNukem, Monkey Island, Ultima VII....all cool stuff.
Battery life is great. With 2600mah AA's and a good charger you get 4-5 hours play time(including video! which was one of my deciding factors.) I got an 8 pack of rechargable AA's and I'll be able to game/watch videos for an entire flight to Europe. I've had this current set of batteries in for the past 2 days and it's still going...has to be going on 4 hours or so of playing games, watching movies, tinkering, etc.
The community is good and growing. I expect good things as this matures...it's amazing what's come together so far in this short time.
I definitely recommend it to anyone who has interest in this sort of thing (make sure you get the mk2 model with the new joystick/cap). Cost is about $180 (not counting SD card and batteries/charger).