Not sure what you mean by "faster" -- ? A chassis is only as fast as the drivetrain powering it. With the advent of the W126, there was almost a complete change in drivetrains with little to no carryover of V8 engines and transmissions -- the 3.8, 4.2, 5.0, 5.6 Liter motors as found in the 126 chassis were new-generation and wholly more modern and more efficient than the 3.5, 4.5 and 6.9 V8 units as found in the 116 chassis.

As such, they did their job much better than the 116 V8s, being smoother, more tractable, better gas mileage, more HP per liter, and lighter to boot. A Euro 500 or 560 engine powering a 126 chassis car was very very close to as fast as, or in the case of the 560 just as fast as, a 6.9 with far less displacement and far better economy. So much so that MB never felt the need to create a "big block" successor to the 6.9 -- the 560 did the job more than adequately with the corporate "small block".

As far as picking which chassis I'd prefer to go faster in, without a doubt it would be the 126. Better high-speed running characteristics and less noise. Perhaps the 126 is not quite as heavy in the materials department, but its USE and APPLICATION of materials was better thought-out.

Today, a 116 chassis car feels, well, old. There's no bones about this. It's a 35-year-old design. A 126 despite being 25+ years old,kept in good condition feels every bit as good as a modern car.

Looks of the two cars are debateable. Ask any 108/109 lover about the 116, and they'll stick out their tongue. Ask a 116 lover about the 126, and you'll get the same reaction. I think in reality, that there isn't too much difference at first glance between the 116 and 126 on the surface. Just refined and a bit more streamlined. Same layout and similar side profile, less chrome.

Cheers,
Gerry

P.S. Qualification: I have owned a 450SEL 6.9 since early 2000, having just sold it. And I have owned a 1983 380SEL and currently own a 1989 560SEC.