Hi
I don't know what you guys base your opinions on, anyway WingTsun is a registered trademark. Wing Chun is the name of all styles within Wing Chun, Ving Tsun is the chinese (canton) name for Wing Chun.
Some say that Wing Chun and WingTsun are like day and night. From my own experience I have noticed that most of the concpets and the forms remain the same, but some parts have changed. Wing Chun is mostly a hard style while WingTsun is a soft style. These opinions are based on the Simon Lau's Wing Chun linage and Leung Ting WingTsun.
My Advice to you would be that you should try both and then decide.
