I'm not a student of HGHS or anything (considering I'm a guy, lol), but my older sister had the choice of going to either North Sydney or Hornsby back when she retook the test in year 10, but she chose Hornsby. As for the environment, from her rantings, there are the usual groups that can be found in all other schools, with the 'populars,' 'more nerdy than the rest i guess because everyone's pretty much a nerd there no offence meant you get me,' 'sporty as frick, popular as frick, smart as frick,' 'gamers,' etc. The teachers also are incredibly supportive, as when she got anxiety and depression in the last year of HSC, her rollcall teacher took notice, informed the year advisor, who got her support from the counsellor and other teachers. As with most selective schools that aren't James Ruse, a couple of people a year move onto better ranked selective schools if they get in. Also, side note: a friend of mine went to Hornsby but transferred to another school as she had to travel for an hour to get to Hornsby and she found it too stressful and time-tight as she sucked at time management. Anyway, my sister still keeps in touch with around 4 of her Hornsby friends in uni, so that must count for something?
Lol, sorry about the lack of paragraphs, I'm too lazy--