Posada has had a subpar season this year, but his OPS ranking among qualifying major league catchers(those who had at least 325 at bats) the last 5 years is pretty impressive:
2005: 10th(out of 27) 2004: 2nd(out of 23) 2003: 1st(out of 25) 2002: 3rd(out of 21) 2001: 3rd(out of 22) 2000: 3rd(out of 19)
Only Mike Piazza and Ivan Rodriguez have better offensive numbers than Posada in that span, and the disparity between Posada and those immediately following him(Jason Varitek, Javy Lopez) is significant enough to make up for whatever defensive shortcomings he might have.
I'd rather have Varitek right now, but to this point Posada's career has been better.
