Part of the issue was he took such a beating in the regular season he was rarely healthy when it came to the postseason. When he was (see Pats game in '06) he had a monster game, but the team around him melted down.
The only game where he was healthy in the post season and he didn't really play well was the Jets game in the '04 season. And to be honest the Jets dominated the LOS in that game..
To me his legacy is, he's the best player the Chargers have ever had.