I had problems with it working properly when I forst got it - would shut off after a few seconds - then not worl at all. It finally seems to have correected itself.
The unit heats well but has two flaws. It is difficult to press the buttons other than the door opener. We've been using the end of a chopstick as it works better than a finger. Also the # of turns is inconsistent so a cup goes around and comes back in a different place each time. The old GE didn't do that.