Personally I would not be without it. Whether someone wants to intentionally damage your vehicle, hurl abuse at you or beat your brains out, or just be extremely vindictive and try and get you suspended because you returned them to the Taxi Rank and asked them to leave the vehicle because you refuse to accept there behaviour towards you; it can provide solid evidence of such an incident or for an accident, and has now prove it’s worth many times over for us.
However, you don’t just fit it and roll, we have a responsibilty (like it or not) to the Information Commissioners Office, which if you ignore, could slap a real nasty fine on you. There is a Guidance Document available which you really need to read: https://ico.org.uk/media/1542/cctv-code-of-practice.pdf
Best Option?
I still think this is the best unit available, as it is easy to fit and sits nicely just behind/below your rear view mirror, and gives a pretty much all round image.