I have the original Comma 3 in my car (2019 Acura RDX), and it's pretty game-changing for long drives. The car already has adaptive cruise control and lane-keep-assist, but you need to keep your hands on the wheel. With the Comma, I can set it up on most of the roads I drive (local or highway) and it'll keep me going at the desired speed in the center of the lane (up to a certain max turning torque, which is a limitation on the Acura LKAS system - if you're in the Bay Area, it handles 101 just fine but will struggle on the 280).

I've logged about 3k miles of autonomous driving at this point and wouldn't hesitate to recommend it if your car supports it, with the understanding that it's a limited system and you still have to pay attention the entire time. Unfortunately, it seems like a lot of the newer cars have tighter security around CAN bus communication, so it may not be easy for Comma to continue to do their thing.