I'm an American, but have lived in many countries, often where tipping is not the norm. In general, my experiences with service personnel have been vastly more pleasant in non-tipping countries. I feel that when people have to angle for a tip, it poisons the interaction. It's irritating for the customer and demeaning for the worker. I even avoid going to restaurants when back in the USA because I expect it to be much less pleasant than I'm accustomed to in Asia.