I'm not sure he was overrated. He wasn't the best defensive shortstop, but his offensive game was above average. As mentioned, look at his career numbers. Then add how he seemed to step up his game during the playoffs.
The backhanded toss on an over throw by the outfielder against the A's is a classic example. If he doesn't have the awareness to go after it, the A's tie the game and have a chance to go up 3-0 in the series. Not only did he get the ball, but his backhanded flip was on the money. He'll be voted in the HOF on the first ballot.
Interesting note. Early in his career, Steinbrenner wanted to trade Rivera for another shortstop and send Jeter back down to the minors. In the immortal words of Paul Harvey; "And now you know the rest of the story."