Perhaps the greatest R&D was done on the 124; this was a fantastic body. After owning my 6th benz at 33 now, I will say that the old E class was quite the car. It had so many innovations beyond any other car out there. The newer 210 body, while larger and extremely innovative and sexy in style lacks the downright durability. For one, the headliner is cloth on the 210 as opposed to the stitched vinyl but even the dash, carpet, and instrumentation was better quality. Never would you have a cracked dash or worry about a broken spring perch on a 124. Not only that, the electronics have proven not as durable; my speedometer, ABS and traction support do not function. Fortunately, I have a 96 which took the running gear from the 124, so the engine and trans are fantastic. I love the car but I must say, I had a 124 Diesel with almost 200k and absolutely nothing went wrong aside from an alternator and a water pump.
Ship, I'll agree with you that the quality materials of 124 is much better than the W210, but fortunately for myself also I have the heart of the engine is a M119 and 5 speed auto.