It is a very dense city with mostly flat areas in Manhattan...but there are other Burroughs surrounding the island of Manhattan where I will likely live (for cost reasons), which are somewhat hillier. That also means there I'll hit at least one bridge daily as I commute to and from the city proper. So perhaps gears would be better. BUT, on the other hand, instead of using the bridges I might want to hop on the Subway to get across the East River (separates Manhattan from the Burroughs--Brooklyn and Queens.) In that case, I might want something lighter to carry on with me as the Subway system is a maze of underground stairways.
Either way, all, I'm definitely going to buy a bike in NYC, so does anyone know of a respectable/friendly bike shop up there? Perhaps where I could get a refurbished bike?