I must tell you that IC2 is way-way more responsive and lag free compared to IC1 so whoever was telling me IC2 is equally laggy, you have not been using IC1 for a wile I guess.
I can also confirm hw3 backup cam view is jerky somehow.
You only need: MCU2, IC2 and the new tuner (can skip that even, e.g. I don't have it yet, but then updates are complicated).