I have been using them for a few years and love the type that strap to your rear view mirror. My current one is a Vantop brand and is great. Once installed it defaults to a rear view upon startup, so it is like a mirror in that respect. The advantage is it’s crystal clear in all weather and has an amazing field of view where my rear wiper sweeps, so in the rain it is just as good as when it is dry. A simple swipe switches to split screen front & back, and another swipe to the front view. Both record constantly while driving and a 64 Gb chip saves about 5 days worth of video. Lots of feature besides, and easy to install for about $100 on Amazon.