I myself have a 0ga 3/4 inch bent with 5/8 dia balls on each end and it feels completly comfortable to me.
It would all depend on the placement of the percing,Mine is directly behind the head and the 3/4 works just fine A buddy of mine has one also but the percer did his a little deeper (ferther away from the head) and he needs either a 7/8 or 1 inch to be comfortable.
I really dont wear mine that much only when I clean my circular ring and when I feel I need a change,much rather have my circular in!