I think sillyboots's point was that the school's placement power wasn't really the factor. USC places better than Hastings because firms have a lower grade cutoff for USC students than they have for Hastings students. Transferring to USC doesn't change the fact that your 1L grades came from Hastings. Firms are going to look at you and see a top 10% Hastings student whether you're at Hastings or USC.
The argument seems to be that going to UCLA/USC/Berkeley isn't going to give you access to interviews that you wouldn't have had at Hastings.
Damn, my late night five paragraph post came down to four sentences. Thanks for breaking it down BK.
Yeah, pretty much what BK said. Point is that as it has long been thought and as that thread with the v15 interviewer seems to confirm, most large lawfirms have "grade cutoffs" for every school in the T1. Generally, any firm that would interview you at your new school would have interviewed you and given you the same amount of consideration at your old school. This is especially true when you're talking about schools in the same region/state-- if they're willing to accept top 10% hastings grads and give them strong consideration, they would invest the relatively small amount of resources to send someone to hastings OCI.
Some people speculate that the new school gives you a prestige bump because firms would rather have a harvard grad on their roster, for example, than a cooley grad. The difference between the schools you're considering probably isn't enough for that bump to make a real difference anyway, but even if it were I've personally always been skeptical of this argument. When they have 500+ lawyers, I don't think they care what diploma you put on the wall of your doc-review closet.
Point is that transferring, for example, to UCLA would just be banking on a marginal edge that there might be a couple of firms that would consider a top 10% hastings grads but are too lazy to send someone to san francisco. Weighing this chance against the edge that you keep by staying in hastings (law review, scholarship, a school that appreciates your loyalty and will do what it can to help you boost its placement record) makes it a relatively straight forward choice IMO.
Again, though, it's up to you. I imagine LA has more sunshine and Berkeley always sounded like a cool place to live, so you might be personally happier elsewhere even if it doesn't do much for your career. Even though we don't put much weight on personal happiness in law school, it's still worth some consideration