hesitation and surging
it's either the gas can't get in due to fuel FILTER AND/OR DIRTY FUEL INJECTORS, DROP IN FUEL PRESSURE, CLOGGED AIR CLEANER , OR just needs a tune up.
I would put a can of chevron techron in a full tank of super dupper premium gas and see if there's a difference. If there is, then it's the fuel system .
the surging issue on the other hand might be a vaccum leak issue.
A good MBZ shop should be able to diagnose this correctly.
1978 280 CE silver
1986 560 SL black
1987 300 SDL cream
1994 SL 500 brilliant green
1997 E 300d dessert silver
2005 FORD F250 Superduty Crew cab 4x4