I ordered the mouse because my physical therapist has detected the first signs of tendonitis in the wrist. Since I still have a few decades office work in front of me, I decided to buy a more ergonomic mouse bought the WowPen Joy, because one of my work colleagues had already this. I have now for about two months and I'm so super deal. It took about two days before I got used to the new handling. I always notice that I have with "normal mice" the relaxed hand position miss at other workplaces, which gives me the WowPen Joy.
The mouse is relatively small (I glove size 7, so her can estimate a bit, so an average sized woman's hand), other ergonomic mice were too clunky or I could not comprehend properly because they were too big for my hand. She also feels pretty easily.
I would buy me back, but it could not say anything about the durability. Therefore (once) 5 stars from me :-)