Right, Mercedes finally put in a new Ignition control module and it solved ALL hesitation problems. Amazing really. I actually went out with them on the road test and drove the car myself. I could not replicate the problem at all. Only 30 mins before on my way to them i could replicate the problem on demand!

UPDATE:
Right guys, since MB removed my old Ignition Control Module, fitted a new one to test, removed it...Then fitted my old one back my car has been difficult to start. Before it started at the flick of a key. Now it will crank for several seconds at least before it starts...
What gives!??

had the same trouble with my 86 2.3-16. When i had the car towed to my Mbenz mechanic's shop, his diagnosis was the car had no spark. This was after I replaced all the level 2 ignition components ie car rotor plugs and coil. I swapped out the ezl module, a 30 second swap, and the car fired right up. The unit i used was from a regular 190e I believe. Car runs fine now