Sheesh, a W126 as a beater. I bet the Mercedes engineers are laughing in their graves, seeing an S-Class being classified as a beater
On the 617 and 603 engines, my 300D Turbo (after adjusting the ALDA) feels jumpier/livelier off the line (gives you a little whiplash) than my mom's 300SDL. I would adjust the ALDA on the 603 but it looked like a PITA so I just left it. That 603 absolutely kicks the 617's ass on the highway though, sometimes I'll look down and see im going 90 mph, it gets there pretty easily and quietly.