Living in NYC with children and we have a very comfortable lifestyle. We live in Astoria, Queens, which is just a short (25mins) subway ride to where I work in midtown. I don't believe anyone in their right mind, in our profession, will be living in Manhattan with children. (certainly no technologist that I know of, and I have met dozens throughout the years). But the big advantage is that, as others mentioned, you can live nearby in Queens or Brooklyn, (or NJ/Long Island) and be within a very short commute to work. Rents will be a lot cheaper - we pay 1,600$/mth for a large two bedroom which is actually an entire floor of a house. I have to admit we were lucky there - but there are enough options if you do a proper search.
There are a lot of tech events in the city, and a lot of other kinds of events and conferences. But the biggest draw factor for me when moving to NYC was the sheer number of companies that are packed together in a relatively small space. This is truly heaven for a technologist who is consulting, because you will have business constantly - especially if you are on top of your game; I can attest that you can make and save a lot of money like that. There are a lot of full-time jobs as well, some which pay well and are 9-5, others that require more hours and pay a lot, particularly in the finance sector. Be careful with startups that require a lot of hours and don't pay particularly well though - you won't get a good deal by working for one in NYC, due to how they compare to all other options I mentioned.
Finally, the other cool thing here if you are looking to start your own company, is that you can meet people to partner with - again due to the large number of people within the area.