Most cars should easily reach 200K miles without any major repairs, unless maintenance is not kept up on (mainly fluids). I have run 6 cars over 200k, and then get nervous about long road trips (for breakdown reasons). I ran a S-10 pickup over 275k and beat the truck hard in construction work, sold it, and the next owner drove it for 1 + year. Then a 72 Grand Prix, with 375K miles. I don't do major repairs, like trans or engine work on old rides. They snap and they go away on a hook or are sold for parts.
I say this because if a Benz can't beat a GM or Ford in longevity, they are screwing up.
Both of my Benz's have over 145K, now and I plan on keeping them for a good 5 years more, unless they become a hole that money gets poured into. Then they (or any car) go out with the trash.
Saying that, I bought the Benz's for their engineering and longevity, I believe they will last. I hope I don't get proven wrong.
Aardvark