Yes! I've used it almost everyday since I've had it. You wouldn't believe how many little knots and impending injuries I've diffused with it. I got the Elite. It is lighter and quieter than the Pro and it's quite powerful. It's very hard to make it stall.
Impossible to say if the knock offs are any good, but the real deal does exactly what it's meant to do. It's their fourth iteration so I think they've got it down pat. I wouldn't get anything less powerful because as you get used to it, anything weaker will begin to stall for the larger muscle groups.
They come up on special every so often. I think I got it for 30% less