I do not believe in stiffing the wait staff. I was going do it once at Disney. At the time If you are on the dining plan, the 18% was automatically added. So my wife and I were at a buffet, the first question was were we on the dining plan and of course we said yes. He took our drink order, brought our drinks, and totally disappeared...I mean no cleaning of used plates, no refills, nothing. We had to flag other staff for drink refills. We know he existed as when we went up for desert, when we came back to the table there was the bill. I was so angered that I was going to complain to the manager but my wife did not want me to make a scene, so I let it go (intentional reference).