I also disagree concerning NYC stores. I agree that Sound by Singer is worth checking out, as is Innovative Audio and Lyric HiFi.
I have found SOME salesmen who are in fact quite knowledgeble about music, some to a surprising degree. If you go to Lyric in Manhattan call in advance and make an appointment with Bob. He is an aspiring musician who is more passionate about music than many audiophiles that I know. Talk to him about guitar players, Django in particular, and you'll get as much time as you want. I remember many years ago Andy Singer (Sound by Singer) talk to me about Ken Peplowski before anyone knew who Ken Peplowski was.
I have never really understood the degree to which dealers are resented by so many audiophiles. There is no question that there are dealers and salesmen who make customers feel very uncomfortable or are not very helpful, but I have also witnessed "audiophiles" walk into a shop, with major attitude and proceed to put down equipment in that shop and proclaim that this or that component "blows away" the equipment on display. That will get them far.
I believe that if a person walks into any of the mentioned shops and approaches a salesperson in a direct and respectful way and expresses an honest interest in certain equipment, a positive experience will be had. Bring your own music; MUSIC, not some cliched audiophile favorite, and speak intelligently about that music and the salesperson will know that you are serious. Capitalize on the love of music, or at least of sound, that you share with the salesperson.
I think that the very strong attitude of some of the previous posts make my point. "No decent stores in NYC", give me a break! Probably the largest audiophile market in the world and there are no decent dealers? I don't think so. "Forget Manhattan and go to HIFI Exchange" Nice guys but a very loose operation IMO. I would agree that Harvey's is a joke and Stereo Exchange is a zoo. Stereo Exchange used to have a couple of good guys, most notably Wes Phillips, but when you can go to some of the other dealers, why bother?
Enjoy your stay in NYC, it's quite a town; and now in particular is an interesting time to visit. There will be lots of interesting stuff going on as far as live music during that time; hope you can take advantage of some of it.
By the way, I am in no way connected to any of these dealers, in fact 75% of the equipment I own I have bought used elsewhere.