I have read that some reviews on Amazon and other places where people LOVE it. I think the learning curve is steep.
It seems it is the "men" who persist and learn to use it and the women who find it annoying and easier to cut by hand.
I have one and don't use it. I tried and my mom tried and we just never got the hang of it. But, we only tried a few times.
Now, the Bias Tape Maker is another story. I use it often. :)