>inb4 you can't just plug in your device for battery concerns.
I personally liked it. If I had an iPad or Kindle (basically anything with a larger screen), I'd switch to bluetooth keyboard/joystick.
I had to use a special jailbroken program to use the joystick in place of the tilt sensor. Which was a pain to configure.
However, I do not own the joystick; I was just trying it and a Wii-mote my friend programmed to run on bluetooth. It was pretty cool, he was playing various emulators on his iDevice via Wiimote