There are a lot of myths about UC admissions. This is not the time and place to go into all of them.
The main point to bear in mind for all aspirants to the top UC campuses is that hands down GPA matters. GPA is far more important than SAT/Subject Tests/ACT scores. A high GPA will often trump lousy SAT scores.
Take UCLA for example:For Fall 2009 applicants, the following is what happened:
GPA
# of
applicants % of all
applicants # of
admits admit
rate % of all
admits
4.0 & above 24,648 47.91 10,631 43.13 92.86
3.70 - 3.99 10,914 21.21 479 4.39 4.18
UCLA Undergrad Admissions: Profile of Admitted Freshmen, Fall 2009
So, only 479 high schoolers with UC GPA between 3.7 and 4.0 were admitted to UCLA out of 10,914 applicants -- an admit rate of 4.39%. Berkeley numbers are expected to be similar. Obviously UCSD and UCD will have higher admit rates than UCB and UCLA from this group.
From kids on CC who post their statistic to show how with a 3.7 they got into Berkeley or UCLA may lead people to think they have a good chance. You don't. For UCLA, those next year applying with a GPA between 3.7 and 4.0 now know they have a 4 to 5 % chance versus over 43 % for those whose GPAs are higher than 4.0. This is the single most important determinant of admission at a top UC.