I didn't get into Harvard, but I chose Boalt over some of those other East Coast schools (Columbia et al.) for a lot of the reasons you mentioned (family, friends, significant other all in the Bay Area, already lived here and liked it, etc.), so that's where I'm coming from. The opportunities at Harvard certainly outweigh those at Boalt, perhaps significantly if you're shooting for ultra-competitive things. No question about that. That said, it depends on what you want out of your career. You will have stellar opportunities coming out of both, especially if you figure out what you want and push to make it happen.