Comparing my friends SWB S320 to my SDL:

The S320 rides many times better, even with 18in AMG's. It just soaks up the bumps. It also feels smaller and quicker than the SDL. It weighs slightly more but has 80 more hp and a 5spd, so its quicker.

As for size, length is about the same, the W140 is slightly wider and taller.

I'd only consider a 1997-99, so it has the 722.6 and all the updates.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200