When they say it they’re always seem to mean it as a compliment but I kind of get offended because of the connotation behind the term ‘nice guy’. And in the back of my head there’s that suspicion that they could possibly be making a dig at me.
I dunno, I feel like in the West being called a nice XX denotes that you’re weak, or insecure, or unattractive.
General rule of thumb:
If other people are calling you nice, then you likely are. If you keep insisting to others that you are nice, you probably ain't.