Have a 2014 CLS550; thinking about upgrading the 19in wheels to 20in wheels and tire. Has anyone experienced a difference in ride comfort?

 

I changed to 20s. 265/30/20 fronts; 305/25/20 rears. The difference wasn't large enough for me to notice and definitely not a deterrence to changing. I do like a rough ride though! I always have the car in sports plus suspension setting. Makes me feel the car is more grounded.

Looks-wise for my car the difference was night and day! Do it. You won't regret it.

 

+1, you'll not notice much, might even like it better, good luck to you.