In the ten years or so since it was last discussed on these pages, I've not been aware of any particular crimes of any significance which would have prevented or solved.
Car theft appears to be on the increase, but that happens off the main streets where there wouldn't be CCTV. Some drunk damaged cars in the carpark one night and there is a bit of general yob damage that goes on. The Jewellery shop keeps getting raided in daylight with lots of witnesses around and cctv in the shop.
I think it might have helped solve the mystery of which driver killed the chap wandering in the Addingham Bypass by giving the Police leads on which cars were around at that time, but thats not conclusive.
So all in all the argument for CCTV remains pretty weak in my opinion.