Yes, great service is a must. The service ends after I leave the restaurant, not after I pay my bill. I am a creature of habit and will often return to the same restaurants unless service/food is horrible. If a waiter/waitress stops service me after they get the bill, I will remember and will refuse their service in the future. I make a point of doing this in a non-confrontational manner as I might not know what I might find in my meal. If service is that bad in the first place, I never go back. I am a great tipper for great service.