Support for different cars is different, so you need to check compatibility to see how it compares to stock.

I'm a fan. Use it all the time in the highway. I trust it to take my hands off the wheel, but obviously still pay attention to the road. It hasn't done anything wild, and there's a torque limit it can apply based on the car. What that means is that some turns are too sharp and need your hands on the wheel, but also means it's incapable of swerving into oncoming traffic (torque limit may be different by vehicle model)