I've got a W202 C240 (98'), and I feel exactly the same. When I'm crusing at, let's say 60 mph, if I need suddenly to pass or anything else, I have to anticipate at least 1 to 2 seconds (that is very long when you need to 'take off' !) my action ...
I think it's more an electronic matter, because when you push suddenly the trottle, the engine doesn't revs up before at least 1 second, maybe to let the necessary time to the transmission to select the appropriate speed.
Is there anything to do about this ?
A french MB fan, from Paris !