I have a Nextbase dashcam.. I think its the 312GW, I'd tried one of the cheap lidl specials and it worked fine until Mrs motorbiing stood on the cable in the motorhome and ripped the USB socket out. The nextbase I have was around £100 but only does front. I wasn't interested in rear. It does GPS and speed also, has a parking sensor mode which is handy and a microphone (less handy).
My only comment is that they are very wide angle, and when you combine the audio with the footage, you do sound a bit aggressive.