theres no doubt that any decent claims department would use such footage to support their clients claim. I always instruct my claims handlers to look for CCTV footage for liability disputes etc.
even the cheaper ones would be worth while, ok you cant make out the reg' number but as long as the make and model of the car is visable then its worthwhile. ok if the other car doesnt stop then the lack of reg number is an issue, but the majority of the time both parties stop and exchange details then you just need to say the X colour car, make and model did xyz as per the camera.