I use it on a 220V system, and it works great, but there's one problem (at least for me) : When the PA is connected to the power (through an adapter), if you touch anything metallic on the PA (the "battery", the area around the temperature dial, etc) you get a little shock. It's nothing dangerous, just ... makes it more challanging to use
What I did to workaround that issue was put tape over the metallic areas that I touch, and the tape isolates the electricity.
My guess is that my adapter between the American plug and the 220V socket doesn't have grounding, and that's causing it (then again, I don't know anything about electricity).
I use the type of socket shown here:
http://designblog.nzeldes.com/wp-content/uploads/2009/05/mainssockets1.jpg
I informed MF about this when I got mine and I believe they're handling the issue.