I may have said this the last time a ball was hit there, but I think AT&T/Pacbell keeps it in. That right-center gap and wall combo they have is pretty ridiculous too.
OPS does break down a bit at the extremes, but in general it's pretty effective.
GPA? Why bother? If you're not going to use OPS, you may as well go straight to a linear weights measure like wOBA that includes base running.
A place for baseball's many amusements that don't warrant a thread of their own. http://nbchardballtalk.files.wordpress.com/2012/08/ericchavezcodyeppleyballhead.gif