In reply to The Lemming:
I have a Nextbase 202, which I got because it's fairly cheap and gets me 15% off my car insurance. And allows me to prove liability after the second person in 3 months drove into the back of me when I was stationary (*). Can't compare it to anything! Like all these things they all claim "HD" but really it's down to the lens rather than the ability to write pixels onto a card, but it seems to record what's going on at a reasonable quality.
You can turn off sound recording, I did that.
(*) of course, it hasn't happened since getting the dashcam...