I think having the gratuity built in would be perfect. I do think that 15% is rather low and that it should be at least 25%. I have never understood why people are willing to pay so much for the food, and so little for the service. When I go out to eat, the service is really why I am there. I tip $10 per person when spending about $15 a person on food and drink. Eating out to me is magical. I get to go in, pick out food, get it served, eat it, the dirty plates just go away. All of this without lifting a finger. It it is a holiday such as Christmas, I will throw in an extra $20. Most of the time there are about 6 of us, so at least a $60 tip.