I did three away rotations in New York City in the fall of 2011, because at the time I was targeting NYC geographically. It was a tough decision, but I ended up staying at my home program. I'll restrict my comments to the places I rotated at, as I feel spending one interview day at a program doesn't really give me the right to speak for it.
1) Columbia: Phenomenal program full of phenomenal people. Here, you will work with some of the biggest names in the field, and what's more, they're all remarkably nice to students. I got a letter of recommendation from one of the attendings I worked with here, and am still in contact with some of the residents, who are also uniformly awesome people to be around. My last comment as far as people are concerned is that the program director, Dr. Levine, meets with every single rotator, gives his cell phone number to every single rotator, and knows everything about every single rotator. What's more impressive - on interview day, he and Dr. Bigliani know everything about all of the interviewees. He's a great teacher and advocate. As far as operating goes, this place gets a lot of complex stuff. On a joint service, you'll see tons of revisions, which is what I did on my month there. ALERT: there is a **RUMOR** that the residents don't operate enough here and that there are too many fellows. THIS IS NOTHING MORE THAN A RUMOR and is COMPLETELY UNTRUE. Though there are many fellows, there are also plenty of cases, and the PGY-2s still manage to get their hands dirty as much as they want. I would highly recommend this place both as an away rotation and as an occupant for one of the top spots on your rank list, as it was for me.
2) St. Luke's-Roosevelt: Fantastic group here as well. Though it is true that this program has a lighter didactic schedule than most, it is far from non-existent, and the residents still have a solid knowledge base and do well on their boards. There are no fellows here (except the hand fellows), and the residents here operate a LOT. In fact, the residents at St. Luke's-Roosevelt do more than any other residents I've seen (keep in mind that I did three aways plus my home rotation...so I saw a lot of residents at work). It is not uncommon to see a PGY-2 putting in a gamma nail, operating the saw in a total knee replacement, or running a late-night trauma as the attending watches in the background, un-scrubbed. If you are looking for a great community-style program in the middle of Manhattan, this place is for you, and it is arguably the best-located residency in New York City. Residents here learn to operate and go on to achieve great things professionally. Finally, Dr. Unis, the program director, is one of the nicest and most supportive guys in the business, and all the residents look up to him. Though St. Luke's is different from Columbia in many ways, it also occupied a top spot on my rank list and I would highly recommend it for an away, especially if you want to try out a smaller, very close-knit program (three residents a year). You'll have a blast here.
3) NYU-HJD: This is an ENORMOUS program in more ways than one. To be literal, there are twelve residents per year here, meaning that there are sixty residents at any given time in the program. Many people love this atmosphere, though I prefer a smaller group. Regardless, I had a great month here. The attendings were great, as were the residents. Again, a lot of very complex stuff coming through, not to mention you take trauma call at Bellevue, which is an experience unto itself - sometimes frightening, but ALWAYS interesting. Again, there are a lot of fellows here, but they are incredibly busy, so the residents still get plenty of opportunity to operate. Drs. Zuckerman and Egol are tough but are very well known and highly accomplished, and I consider it a privilege to have been able to learn from them, if only for four weeks. Again, I would highly recommend this place for anyone looking for aways in NYC - it was a great experience to have as a student!
I clearly wanted a wide breadth of experience when I chose my aways. Columbia was meant to be the "academic," SLR the "community," and NYU the "traditional, large" program. In the end, every one of these programs proved themselves to be very well-rounded and strong. As I mentioned before, I stayed at my home program for personal reasons, but these places were all in my top five and I would have been ecstatic to end up at any of them. Good luck!