I live in NYC now and have spent enough time in SF, MV, and PA to know what it would be like to live there. It’s certainly expensive in Manhattan, but there are a number of advantages:

* I don’t need a car. This has been as freeing for me as for others.

* I don’t worry at all about logistics, ever. The subways run all night, taxis are ubiquitous, and walking is safe and pleasant.

* Everything is close by, so I don’t need to worry about meetups at the opposite end of the bay.

* I can find good food nearby regardless of the time of day. This city never fully sleeps, which is great because you can set your own schedule.

The city is also distracting, but after a while you get used to it and build up the self-discipline to stay in and work. I’m not convinced this is any harder here than it would be in any other place that I had friends.