All the recovery / roadside assistance companies are good, until that is, they are not.
I have had good experiences with BMW’s branded assistance, operated (at the time) by Axa. Others swear it is shite. Hey-ho, that’s life.
Don’t forget that, if you are hooning / bimbling outside of the safety of the UK, the chances are that you won’t be ‘serviced’ by a Green Flag branded truck and smiling man. You’ll probably get Luigi, or Cédric or Manuel or Spiros, with his greasy low loader and remarkable lack of English. If this troubles you, stay within 10 miles of your front door and SWMBO’s / mum’s apron strings.