I tow a boat and the camera in the middle marker light is invaluable when backing up to the trailer, personally I haven't noticed a significant difference in the appearance at night with the middle marker light blacked out. If you do any kind of towing the license plate cam and the hitch cam will not work as well for you. If you have a rear spare tire carrier, then the marker light cam may not work well for you. Confused? Me too.
Do a search on here, there are a bunch of threads with everyone's "personal" opinion as to what they like best.