My brakes on my '98 E320W4 aren't what they should be. When I first apply the pedal they start to work but as I gently increase pedal pressure the braking does not increase in a linear fashion. The braking will eventually come on strong, sort of all at once.

The rotors look like normal wear for a 65K mile car. The rotors do look a little shiny. Could the rotors be glazed? I just got the car so I can't vouch for how it was driven.

The brake master has clean fluid and if up to the right level. There is normal brake dust and there is no squeaking or other noises when the brakes are applied. Nothing else out of the ordinary.