As someone who spent 4 years working in a restaurant, and now tends bar part-time for extra cash, here's my take. I think steve-b is one of those patrons that goes out with the calculator running in his head. His evening consists of running his waiter/waitress/bartender in circles to calculate the level of service. However, no matter how many times you promptly fill his coffee cup, wipe the wet spots off his table or perfectly pour his beer, his high point is 15% while ticking off every real or imagined slight in service so he can feel justified leaving a $1.50 tip on a $30.00 bill.
Do us all a favor and stay home.