I own both of the S1 and C1 Pro and I've done side by side video comparisons in daylight but not night yet. I was hard pressed to find a license plate I could read on the C1 pro that I could not read on the S1. I have them both mounted to my front windshield at the moment. They are nearly identical (both running their highest resolution). There were 1 or 2 places at more extreme angles I could make out a plate on the C1 Pro that was not very readable on the S1, but they are nearly identical. I compared them by copying the file to my computer and looking at the video on a large monitor.