I don't live anywhere as dense and NYC, but I'd echo the sentiment. I live on the city fringe, and the ability to easily get to music, dance, language lessons, galleries, playgrounds, and so on are all invaluable to me and the kids. Pretty much anything they want to do (other than "have a pony") is much easier in the city that it would be in an outlying suburb. And when they get into their teens, I'll be a lot happier with them having good options for buses, trains and so on.