Hello gentlemen
Oh la-la so many ideas in these posts that I MUST reply to.
First ,the M100 versus M116/117 engines : the M100 was the first OHC V-8 Mercedes ever designed - I know this engine from the days when I had a 6.3 : it is incredible in weight balance and quality. The bottom end is so massive and well balanced that I once got mine to idle at 525 rpm !!! if anything, it was overkill...and too heavy. The second V-8 from Mercedes was the M116 and they did take the quality from supreme to very high

and improved the engine in terms of weight.
I once showed a cross-section of an M100 to an experienced engine designer at Renault and he had one comment : the extreme curvature of the exhaust ports (angle of valve heads to exhaust manifold plane was over 90 degrees and would naturally lead to very hot exhaust runners right under the valve gear. This could be a thermal weakness and lead to problems... depending on the quality of the engine

The only real problem with the M100 is high price of parts. That second V-8 is finally a better solution and perhaps the best ever built at Mercedes : the port profiles are more conventional while the engine oil supply is still huge : a 3.5 has almost as much oil reserve as a 6.3. As for the 6.9, it has a huge advantage : still the same "hotspot" exhaust ports but the most glorious of oil systems.
Now Tomi, I think that the W124 is a much better car than the W123, it has better suspension but durability-wise - they are not as good as their predecessor.
In conclusion, the Maybach versus 600 comparison.
The Maybach is a worldcom "go-like-hell" car : it is "vulgar" as Ozbenzhead says because it is a bloody mobile office ! when you get tired, you just throw the seat back and take a nap. You are important but must
get hopping before some other company launches a buy-out on another that you are trying to acquire. You just have to be there on time to do business ! You can email a fine hotel down the road and settle in comfortable accomodations with a swimming pool. You might even bite into a hamburger because you are so hungry.
The 600 was an aristocrat's (people respect me, I as go as I choose) car : it was actually a small personal office where you could take a friend to sample some fine 20 year old scotch after a long walk in a park to discuss international politics. You could talk there, even smoke a fine cigar but did not sleep there - taht is NOT proper. You were not interested in quick communications as people actually WAITED for your appointments at the office, later, next week ! You could also ask teh chauffeur to use the telephone to contact a good friend. And you just drove up to his castle and dined in a large dining hall with some well dressed guests. You might even enjoy some "truffe au chocolat" before the meal.
This says it all to me.
Now the 108 : beware, these cars are also complicated beats, many parts, bizarre rear suspensions and ont even think of a W109 or an M189 engine unless your bank account is ready !
Still, they are wonderful sedate saloons.
Denis
Paris, France