Seeing it on a menu doesn't make you some culinary expert. I bet you've never tasted it.
Fried chicken from the petrol station, that's the extent of your gustatory exploration.
I have as I remember thinking "what the fúck sort of name is XO sauce" totally unaware of what it was.
Didn't make much of an impression on me from memory, but then such is Chinese food. It fills a hole but you are not going to eat it two nights in a row.