I think he's overrated too. But take a look at 2002. It was arguably better than last year. 2001 wasn't bad either (.355 obp 29/33 stolen bases).
So that's two "good" seasons ('02 and '05) and two solid ones ('06 and '01)
I'd have to do a more thorough study of his defense, but on first blush he seems to be worth the money ($3.3 mil/year) to me.
http://sports.espn.go.com/mlb/player...?playerId=4625