I've had an ePrince one for... Oh my, 13 years now. It's been great, the only thing it needed was a new battery after about 8 years. I got one from AliExpress and soldered it in.
I needed it today because some pillock backed into me and drove off! I can't see any damage so I'm not sure if it's worth reporting to the police. I don't want to make an insurance claim, and they want your insurance details as part of the report.
Anyway, it very clearly shows the registration number. It's only a 1080p model with a very old sensor by today's standards, but I think far too much is made of that kind of thing. Okay, you can't see the number plate of someone zooming past in the opposite direction, but who cares? They didn't get close enough to hit you.
If they hit you at high speed they are going to have to stop no matter what, and you have the evidence to prove it wasn't your fault. If they hit you at low speed then even an old dashcam is enough to get the number plate.
The two main things are how well it works at night and parking mode. For night stuff I think the main difference is ones with good HDR stop the number plate being blown out when lit by your headlights. For parking mode they are all crap. The fancy ones have secondary batteries and special time lapse modes and stuff, but the thing you really want is the ability to only run it when you are parked away from home where you have a driveway and CCTV anyway. None of them have that.
The ones that only record after detecting a knock are useless because you need to capture the knock. The ones that record all the time while parked but only save it when knocked are probably okay, as long as they are nice and sensitive.
Worth having a rear camera too. Anyone care to share how they routed wires to the back? Or the front for that matter, if you aren't using the USB port by the mirror.