Apart from looking and talking like an oriental, there are still differences (before we even get to culturally). Yes, I look oriental, but because of my paler skin colour, I stick out in the crowd while I am in Hong Kong (not much different than me in a crowd in an Irish city :-) ) When I speak Cantonese, it's fluent enough, but I still get caught out in Hong Kong, though I must admit I do get complimented on my fluency in Cantonese (not an excuse, since I have been brought up speaking it).
Now to the culturally different part... From what I heard, usually a HK college student of a good time socially is getting together to a hike, camping or have a BBQ, while here... you got it, the pub, get hammered and to the nearest pub/club after (heh). I remember my cousin (who has studied here in Ireland for quite a number of years) wanted to go to a pub with her sister and auntie, but they do no quite grasp the concept of going to a place like a pub where it is very noisy and smokey (and have a few drunks :-) ), and not go to a cafe instead. There you go, some little differences between an IBC and a HK Chinese. Not all of them, but a small bit.