We were with Britannia and they were very good. I dont know of any that will take you home though if you are more than a few miles away as that is open to a lot of abuse.
I used it a couple of times and each time it was the nearest garage. Broke down once and obstructed the road as the drive shaft popped out of the fiesta so couldnt move it, called the Police first then Brittania. The police sent their breakdown company which arrived as mine did and demanded to take the car themselves which resulted in a 100quid release fee. Last time I call them first
My cover here is good and is for me in any car.