I went to the 2007 trials. It was good, but not great. The crowds were not what you would expect having the trials while 45000 marathoners were in town and 1.8 million people were just a short subway ride from the course. If you were the family of a trialist or just wanted to see the trials, you had to pay at least 300 a night to stay on Manhattan island. 300 a day in Houston can get you a hotel, rental car, and 3 meals for a family of 4.
The NY marathon is so huge that it almost overshadows the trials. And it might be too soon to have another NY trials after the Ryan Shay tragedy.
In short, NY is a good place to have the trials, but in no way is such an amazing place for the trials that it should have some sort of entitlement to them.