Ability to decouple gas/brake control from steering, so you can control gas/brake yourself and let comma steer at all times. With OpenPilot, when you touch the gas/brake, the steering also stops.

Ability for the comma to read your car's blind spot monitors and automatically change lanes without you having to nudge the wheel.

Ability to use dynamic mode which dynamically switches between chill mode and experimental mode, so you get the best of both worlds.

Ability to fine tune many settings related to gas/brake and steering sensitivity and control that you can't play with in OpenPilot.

That's the main differences i'm aware of, but there are more.