I never remove mine from the car. If you install it in a sensible location, unless you know it's there it's largely unnoticeable.
I have a blackvue one, records 1080p front and 720p in the back, and records GPS location, gforces in an incident, and what have you, and Ive recommended them to/installed them for a couple of friends now. When my friend had a minor bump the footage was invaluable in helping settle the claim, as the footage showed that the vast majority of the damage they were claiming for was on the car already before the accident and some of it was not on the car after the accident, that he hit them at about 5mph not the 20mph they claimed, and most importantly IMO, it showed them getting out of the car unharmed, with no injury, bending over to look, so they couldn't try the whole "whiplash" thing on with his insurance co.
In this day and age I wouldn't be without one. Just make sure wherever you wire it to isn't going to cause issues (some cars get tetchy with load on lighting circuits if that's where you're planning on tapping into).