Is your long term goal modeling or acting? As an actor are you more interested in stage or TV/Film? Obviously if you are more interested in stage, then NY is the place to be. For TV/Film, LA is a stronger market.
At 5'7" you are looking at commercial modeling more than high fashion. That means that NY has no huge modeling advantages to you over LA. The point is that, if your long term goal is acting, I would make my decisions based on that, not modeling.