I've installed the N4S and S1 Pro Max with their rear cameras in one vehicle (family members) and the N4 Pro S in my vehicle. I had the N2X in mine as well, but I swapped it for the N4 Pro S. I put the E1 Pro in another vehicle (Family members)... As I've installed all these cameras to test their functionality and reliability. Just haven't had a lot of time to play with the N4S or S1 Pro Max beside making design suggestions which Vantrue took seriously.
All their rear cameras are getting a makeover within the next 1-2 months based on my feedback.
I do plan to test out the N5S but it'll be a bit before I get to it. Thus, I definitely appreciate your thread!