The bad things (IMHO) is that there aren't as many interestingly weird music or arts things as there were even 10, 15 years ago. There are no nightclubs. There are no weird music venues in Manhattan. The most avante-garde you are going to get is a band like Grizzly Bear... which is kind of avante-garde but is also a huge national act at the same time. Artists have to live way out in Bushwick, or even further away. I don't really know where interesting art shows go up. I honestly think the number of actual practicing artists and musicians is probably the smallest it has ever been. The indie gallery scene isn't a lot better than SF. There are probably more bookstores in either Seattle or Portland than there are in all of the NYC area, which says something... I'm not sure what.
So I won't lie... I was disappointed in the state of artsy-fartsy music and culture when I returned to NYC. But I do like all this other urban parkland paradise stuff. So it's a tradeoff. I don't really know where people are doing interesting art and music stuff... maybe berlin or beijing? I know a lot of artists who moved to LA simply because it's easier to get a lot of space. Even Jeff Dietch moved there.
If you're looking for something like Andy Warhol's factory scene, I don't think it's happening here. If you're looking for a girlfriend who is a graphic designer for Kate Spade's website - it's your best bet.
I personally know several electronic musicians that left S.F. for Berlin so maybe that's a better destination. It doesn't seem nearly as energetic in tech though.