I think that both are great schools and given the choice I'd rather stay in miami for med school and go to NY for residency if I wanted to later. Coincidentally, I have an old friend that went to Miami for med school and started residency this year at AECOM.
That said, I think both are on equal turfs. both are in big cities and deal with a variety of different and unique cases with very reputable hospitals and clinical training, both of them have a pretty big degree of research, etc.
I personally do not believe one will out do the other to such a degree that you should feel the need to go to the interview if it is really not a top choice in terms of location and support system.
I think that if you could see yourself spending 4 years in NY, 4 years away from family and friends, 4 years incurring more debt then you may at miami despite Miami's high cost (since Fl. residents get some degree of a break compared to OOSers), etc. then its worth it to go. if you feel that you will have regrets of at the very least not seeing what the school was about then I say go for the interview. If none of that is the case then I say cancel it as they'll give the invite to someone else who may need it more. But you earned the invite so you have to think of what it means to you personally.
I know personally that most of my friends have gone to all interviews even if they had a top choice at one point which they got into because sometimes it is really in the interview which can sway a person to choose a diff. school then the one they initially thought was their first choice. They see a diff. side of the school after actually going there for the interview then what their initial perceptions are. You might want to go just for that purpose because you never know. but again its up to you in the end. Good luck with your decision, and remember that both are great schools that will get you to your ultimate goal with a very good education.
