You can wangle the cover where they'll get you home (as opposed to just nearest garage) for about £35.
That's standard renewal price of about £150, less 50% for new member signing up on-line, less £45 cash back from ordering via Quidco (cash back can take a few months to show up).
For that price I like to know I've got it as an option, although I'd like to think I could sort a puncture out myself.
I fully expect to have to switch between AA and RAC every near in order to get a good price, just like I seem to have to change insurance company every year, and energy company, etc. Silly really.
And they may be good or may be crap depending who you get on the day, but for £35 it's a tool worth having at your disposal.
As others have said, while there's nothing wrong with having free breakdown cover with your bank account or insurance policy, just make sure you're clear on what's included. Typically it's the basic cover where they'll recover you at most 10 miles to the nearest garage, not get you home, which to my mind is not a lot of use. You want the get you home stuff, otherwise you might as well sort recovery to local garage yourself.
Similarly I've recently done 2200 miles to Italy and back without any breakdown cover, because for £100 they would only recover you to the nearest garage, and even the fancy good cover left it at their discretion if they would recover you home or to your destination (my hotel? the top of an italian alp?). So I chanced it and was fine, but had a credit card on hand in case.
Andy