On a scale of 1 to 10, where 1 is dire/miserable/awful and 10 is outstanding, ask the team to give a number for:
-themselves as a High Performance Team (10=perfect)
-you as their leader (10=perfect)
-quality of team meetings (10=no improvement possible)
-service provided to rest of the organisation (10=no improvement possible).
If anything less than a 10 is given, ask what needs to be done to close the gap? Then close that gap ASAP.