I have one of those. It's pretty awesome.
Except for the time that it built up a vacuum inside (it's totally sealed and waterproof, and I believe fluctuating temperature and humidity caused it), which then caused the little rubber cover over the power switch to suck itself inward and turn itself on at 4 in the morning, buzzing all over the bathroom counter and nearly giving me a heart attack. I think I had one of those instant nightmares where someone was attacking me with a giant vibrator....
I had to nearly destroy the thing utterly to get it to turn off. Took me a while to figure out why the hell the thing did that, but I finally pieced it together.