Webber is better than Coulthard. Webber has been unlucky this season as he was on for some good points and maybe a podium or two. However, Coulthard is 36 and probably passed his best in terms of raw speed. I'm sure that his experience counts in the running of the team, progression of the car, and gaining vital experience points.

Ayrton Senna: WDC 1988,
1989, 1990, 1991
McLaren: WCC 1974, 1984, 1985, 1988, 1989, 1990, 1991, 1998,
1999, 2007McLaren: WDC 1974, 1976, 1984, 1985, 1986, 1988, 1989, 1990, 1991, 1998, 1999, 2008