Congratulations on your interview! I can't comment on the New York office, but you should be able to search on the timelines for others that had an interview there and see what their experience was. A lot from this group seem to have been transferred to CSC, which didn't entail an interview. There is no rhyme or reason who gets transferred or who gets interviewed so don't worry that because you got an interview, there is something worriesome about your case or anything.
I had my AOS interview in St. Louis. You can read my review, but basically it was short (15 minutes) and seemed to be just for the purpose of verifying information. The lady we dealt with was very nice, and professional. From when I mailed in my application to when I had my interview was exactly 4 months. I got my GC in the mail about a week later. I was also fortunate to get the stamp in my passport as well. I hadn't applied for AP, so I think that's why she gave it to me.
I sometimes wonder if Canadians don't have a better chance at most stages of this process, even if it's just that we speak a common language and have a similar culture. I guess the only time there might be more scrutiny or concern is the financial aspects of this journey. (i.e. affadavit of support)
Carla