I think about this a heck of a lot actually. It's hard to know how things would be if you could "go back" and do it again. The New York (or any place really, but maybe not to the same degree) that you know after 6 months is NOTHING like the New York that you know after 6 years. It's all a process and I don't know if anything would be "better" if you did it differently.
For example, after 5 years in New York, I didn't want to leave Brooklyn any more. I loved the neighborhoods, I loved the more relaxed lifestyle, I loved that I didn't see tourists everywhere, I loved the local bar and choosing from the 15 restaurants down the street. Does that mean I would move directly to BK if I were to do it all over? No way. After 10 years and I was deciding to move away I was really happy to have gotten the opportunity to live in Manhattan for a few years. It was really exciting for a while.
Or would I have tried to meet different people? More people? Less people? I don't know. I'm not a naturally outgoing person and New York actually drew my social side out slowly but surely. It's hard to know if you can force yourself into a different social mindset. I got to KNOW the city so well the first year I was there because I'd spend hours and hours alone with headphones on just walking. From Union Square to Times Square, from Chinatown to Dumbo. I don't know if it would be beneficial to skip any of that.
Professionally, maybe. I don't know how much all of that had a direct bearing on how I lived in New York. Sure, I'd change stuff. I have a lot of work/education regrets, but I think I'd have them anywhere and anytime. I think I'm going to regret my current work choices right now!
Maybe I'd have moved to BK earlier in my time there. Maybe I'd try out a few more neighborhoods to live (QNS, Uptown). But I don't regret the way I lived in New York. All the main life-changing events I had there, I don't think I'd mess with. It made me, me.