First, I'd like to say again that I agreed with most of what you had to say and thought you were well spoken (well, actually, well written :-) ). But I still don't think the lifestyle point is all that critical to making this decision because we're considering two urban areas, both of which offer great city culture and also outdoor activities within 40 mins from town.
I've lived in NYC for six years and have spent time in SF visiting friends and family. Obviously, SF has better weather, but people I know in SF, many of whom were my best friends in college, are just as happy there as they were here, and doing many of the same things. Outside of work, for those who aren't grad students & have more time to kill, or lab/class for those who are but are trying to get some downtime, they're either doing typical urban stuff or they're outdoors hiking, just we do here in NYC. There's amazing hiking under an hour away from midtown. Great softball league in Central Park. Terrific beaches on Long Island. One thing we have in NYC that SF doesn't have at quite the same level is theater, but they still have some good stuff happening in that realm, too. Maybe it's just that I think people who are tech, comp sci, biotech, lab ppl are more alike than they are different no matter what coast they're on. All I'm saying is that I don't think it's a big distinguishing factor to consider, except for weather. One might really prefer the weather on one coast over the other.
Finally, I never claimed that my undergrad experience was representative of the popular college experience. In fact, I was claiming the opposite. In schools like mine, nearly half the undergrad population is from the 3 states I named (CA, MA & NY), while the other half is hugely diverse. Since those 3 states are heavily represented, you tend to meet plenty of ppl from those states and begin to recognize that ppl who grow up on the coasts tend to have more in common than not.
And lastly, my comment wasn't meant to speak to the differences between grad school and undergrad. I've been a tech for 2 years at Columbia, my undergrad institution. It's a world of difference, not least because I'm no longer on the undergrad campus but rather up at the medical center, and like the grad students & post docs in my lab, I'm working full time and really long hours with only 2 weeks off a year. The only undergrads I see are those working in labs up here. I imagine it's the same where you are, since Longwood and many of the Harvard labs are in Boston and even Belmont. So yeah, given my own experience the last two years, I agree with you: undergrad and grad school are little alike, even though I worked in a lab as an undergrad every semester from freshman year and every summer. As an undergrad involved in a lot of different ECs, my lab work didn't define me the way it does now.
And for whatever it's worth, I don't mean to be contentious with you, especially because I agree with and value much of what you've posted here on Grad Cafe. I think you've given great, solid advice. I simply didn't agree with the one, minor, point.