I have the Cycliq 12 Sport on the front, Fly 6 on the rear. I use them to report dangerous drivers, mainly close passes. The police usually take action on the evidence of the cameras. Quality is good, certainly there's never been a problem reading number plates, at least during the day. The battery life on the rear one is far less than the front, which is a nuisance, charging wise. Some of the mounting accessories are a bit cheaply made - the strap to fit the rear to the seat post broke, for instance. Didn't matter, my rear is attached to the rack that lives on my bike.
Footage is timestamped, though you have to connect using the iPhone app to keep the time in sync.
Get a pair, then report every close pass/left hook to your local police forces OpSnap. The more people who get letters in the post, FPNs and points the sooner drivers will start to show cyclists some basic consideration.