CAA vs PCRA
I reached the point last summer, where I had to make a decision whether to go with PCRA (slightly cheaper) or CAA. In the end, I decided to go with CAA because MORE tow truck operators/garages seem to be associated with CAA.
Being practically disabled, I would have a hard time changing a flat tire on my truck as the tires are very heavy, not to mention doing this on the side of the road of a busy highway by yourself can be dangerous, especially at night.
I had brake failure (seized caliper on the highway) and fortunately the nearest town was within a kilometer when it siezed, however I managed to drive it (with the engine straining), into the nearest garage to have the caliper replaced again.
I didn't have any roadside assistance up until then, but having and unexpected brake failure after changing out both brake calipers 12 months earlier, convinced me that having some kind of road side assistance would be a good idea at this point as the other caliper that was installed at the same time, is still on the vehicle. Whether it will fail sooner than expected remains to be seen, but I'm glad now that I have CAA plus to tow me up to 200km if need be and that would get me home in most cases.
Another reason would be having a mechanical failure or flat tire in the evening in the winter at minus temperatures.