Honestly, if I'm travelling, I don't really care if the server thinks I'm cheap. It's not like I'm going to be eating there again any time soon. You'll get 15 to 20%, depending on the quality of the service. And if you don't like it? I don't care.
It would be different if it was a place in my home town that I go to all the time. If the town culture is 25%, I either tip 25% or I stop going out.