It is also measured by survey of public opinion of faculty, administrators, and staff across the country from most, if not all the pharmacy schools. You can't measure the quality of education based solely on GPA or test scores because quality cannot be measured so objectively. Since quality is an subjective trait, that is why people even bother asking this question in the first place because you start to wonder whether it is worth it to apply and attend a certain school.
I do agree with you WVUPharm2007 because it is such a subjective trait. Unless you have attended all the different pharmacy schools, one cannot gauge the quality of education received. However, I do want to say that Maryland is one of the "top" programs as considered by US News and having rotations at Johns Hopkins helps a lot. Similarly, UCSF's hospital is considered one of the top as well, especially considering the medical school which is both in the top 5 for primary care and research rankings. I think associations with these great medical centers tends to sway some public opinion of which school may be better, but it is still a subjective observation.
Cost of living in San Francisco is definitely a negative. San Francisco is one of the most expensive cities in the country, but then again, it is also one of the most diverse.