Thanks for all the input, everyone! Here's a quick round of responses:
@Munashi: I e-mailed them a bit ago, still no response. I tried calling, but the machine just told me to write an e-mail! Lol. I would try e-mailing POIs, but for an embarrassing reason, I probably won't... I was really applying to the program more than I was to any specific professor. I really didn't know what I was doing in the fall...
@the_sheath: Haha, sorry! I'm slow to graduate! XD
@Rantar: The thing is, you mention vaguely UCSD has amazing programs... But I don't see how it's at all better for my field! They don't have as many researchers available to work with, and they aren't as renowned in natural language processing. USC takes the cake on that. So it's nice that UCSD has great programs overall... But it doesn't really help if that doesn't include the one I'm interested in! That's really why I'm posting. I want to know what does UCSD have that should make me consider it? I really don't know! Is there anything? So far, the reputation and living areas are the only things to consider (thank you very much for that input, these are very important!). But I don't think the reputation of the school is worth losing out on a more-reputed advisor, and I know I'll be fine living in LA. (I shouldn't visit UCSD and see how much I'd prefer to live there... I can't regret it if I don't know what I'm missing out on! Lol)
I'll upvote you as soon as mine respawn, because that post was exactly the kind of information I was looking for. And since it turns out the things you mentioned are not enough to sway me, I really might just accept at USC soon!
"Don't trust US news rankings" Already on it! It just helps when posting here to mention them, I think, since so many people bring it up. I'm more concerned about the Microsoft rankings which have to do with the sheer number of publications in conferences, but I know even that isn't an ideal metric!
Also, I remembered the other reason the earlier I decide, the better: my SO is moving with me, and he wants to look for jobs sooner rather than later. But just like the housing, this isn't necessarily a good enough reason to rush a decision.
Still, it's not really rushing a decision if UCSD has virtually nothing going for it. What could they possibly offer me to make it a better program for me? $1,000,000?