scraff
Striker
It'll have little effect on group shots from a distance, but it's never a bad idea to have it on all the time.
It's certainly not gonna spoil any outdoor images in daylight
Problem is though you are limited to whatever the flash sync is and if you are trying to get creative shots using narrow depth of field of say F1.4 to F4 and it's fairly bright then you can't unless you stick a ND filter on.