Easy to install, easy to use, easy to break if you're not careful.
Had it on my mandolin since 2015. The sound is really accurate and powerful enough to play on both big and small stages, competing with all other instruments easily.
Like with any contact mic you get movement noise from plucking strings, light finger squeaks and rubbing against your clothes. Make sure you don't wear anything with buttons down the front and you'll be fine.
The grip works on tension, so I'm always a little anxious when pulling the cable out that I rip the whole thing off. I tripped on my cable once, the cable stayed in the pickup and ripped it off the mandolin, breaking it. Totally my fault, but something to be wary of as it's so delicate.
The good thing is, I've now used 2 of them and the sound quality has been equally great in both.