You will find the majority of people that have it, love it. Those who state they prefer to do their own shifting, more power to them. I got it due to mild arthritis in my left hand, and it’s fantastic. Up shifts on open throttle are smooth and the throttle blip on downshifts is great. It works pretty much throughout the rev range in both directions.
You’ll read some stories of it being jerky and horrible, but my suspicion is those units were not installed properly…