I've used both over the years.
I had one bad experience with the RAC. They came out to my non-running engine, couldn't work out how to fix it, and recovered me to my garage. My garage later called me to say that in the course of trying to fix the ignition system, the RAC man had shorted the ECU and destroyed it. It cost the best part of five hundred pounds to replace and finish the repair. They gave me a letter to send on to the RAC; the RAC wouldn't compensate me one penny.
So the original fitter made a mistake; anyone can make a mistake. But the organisation that can't deliver decent customer service, for the sake of what to them is a small amount of money, doesn't deserve to be recommended. If they had dealt with me fairly, I would have recommended them to anyone. As they failed to do so, I let people know they let me down.
There is plenty of competition in breakdown cover nowadays.