I went to a few NYCC's. Here's what I saw:
First NYCC was great. It was a ton of cool stuff, not too crowded, great guests, one of the best cons of its' type I've ever been to.
Second one was a trainwreck. They far, FAR oversold, there were multi-hour lines for everything (to get in, we had to wait on a line, to wait on a line, to wait on a line). Fire Marshal came down and had to stop letting people in some areas like the main floor because of crowding.
I think I went to two or three after that. After the debacle that was their second con, they took over more and more of, and now I think the whole of the Javits center. As they were spreading, the crowds weren't TOO bad. The problem is, they hit a point a few years back where there was nowhere left to spread, and continued to try to get more and more people into there. So, now we haven't gone in a couple of years. We're far enough away that we'd have to get a hotel room, and anything in the immediate area is in the $300+/night range. The lines were stupidly long enough the last time we went, that we decided the only way we'd go is if we could get VIP tix, and those sell out ridiculously fast.
It honestly just stopped being worth it, from a time and money perspective. I'd rather save the money and travel up to Boston for PAX East. Even with traveling, since there is a $150-200/night difference in price per night at a hotel, it's cheaper to go up there.