I picked a few of these up back in August when the price dropped. The extra dock (sold separately but now very cheap) adds USB and Ethernet ports.
My experiences were mixed.
Out of the box, it's locked into the GameStick ecosystem. There are some decent games there, but they're all also available on Google Play and usually for less $. Chances are that like me, you probably purchased those games for other devices.
Next up was to unlock the stick by converting to developer mode. This is free and relatively easy, just sign up as a developer at the GameStick website. As a dev stick it can sideload stuff but still doesn't have access to the Play Store. Sideloading Google Play is possible, there are instructions at Gamestickers.net forums. I tried several times before things took.
The performance with Google Play sideloaded was touch and go. Eventually the stick bricked during updates.
Next I tried Custom Firmware, also available at Gamestickers.net. This is a basic Android install customized for the GameStick. It was much easier to install and get working than sideloading Google Play and apps on a dev stick. Unfortunately, my experience with CFW was also mixed. It performed well as a media client, but many of the games didn't recognize the video hardware properly and performed at less than full HD. Using the GameStick Bluetooth controller was also hit and miss, mostly miss. I found everything worked better with a USB mouse simulating touch controls than the controller. MAME and other emulator performance was hampered by the failure to output HD video resolutions, something I've never encountered with my other Android devices.
So for the price, yeah, it's a cool toy to tinker with. Considering that it comes with a Bluetooth controller, HDMI cable, and USB charger with cable, those things are pretty much worth the price even if you end up hating the stick.
Don't expect high Android software compatibility or Ouya performance from it, though
