English writing HELP (250-300)

that really depends if he's going to america for post secondary education or for normal elementary/high school.
if the former, my experience tells me that America's style of education is much more open, a lot of presentation, a lot of questions and answers. HK's more formularic. HOWEVER, Hk's education is much more knowledge intensive, america is free for all, its either you take the initiative to study yourself, or you don't.
as for the latter, i would think that all universities around the world are the same. since many ppl in universities do exchange. so the only different would be the culture shock.
lifestyle... well, its about the same, very very fast paced. america's transit system generally is not as well connected as HK's (but that depends on where you go to, if you go to NYC, its not too bad) really, the lifestyle are very similar..since HK is half westernized anyway.