I had what I thought was a real Hitachi and I didn't like, it was too buzzy. But then I read DigitalSweety's review, link
& discovered, via her comparison pictures, that mine was a knock-off. Let me be really clear -- I did NOT purchase the knock off here, I bought it from Amaz*n! I just sent it to a friend & she loves it for muscle massage on her back, so it is no longer a waste of money!
I am considering buying the Hitachi here because I can trust I will get the real one! I bought the very expensive Gee Whizzard, link
to try & make my knock off work for me. Since I still have it, I may as well try it the way it's supposed to work, with the actual Hitachi! Maybe I will finally "get" why everyone loves it so!