What's nice: the hardware is solid, unit is very responsive, display is crisp amplifier is not terrible. if the carkit works, it sounds great on both sides. The cameras are sharp and function. Dashcam and sentry: super. That's why 2 stars. Now to the problems.
1. Bluetooth carkit handsfree calling mostly fails. The person on the other end doesn't hear me. To the point I have my headset when I drive. By mostly I mean 99%
2. So aggressive background app killing: sometimes maps lose navigation even when put in background. But always if I switch the ignition off, say at the gas station.
3. Glitches, steering wheel buttons just stopped working yesterday, had to restart the unit to bring them back.
4. Adas? That's useless in it's state and unnecessary bloat.

All in all, the premium price tag for top of the line cc4 pro would warrant premium unit. But it's far from that. A carkit functionality is so basic thing to get wrong.

I would recommend buying a different brand. I would return the unit if I wouldn't spend hours installing camera wiring and microphone...