I spoke to a rep at Tirerack.com as well as the tire manager at my local Bridgestone/Firestone dealer and they both said the same thing about run flats: These days if the car comes equipped with run flats then the mfg. designed their suspension specifically to ride with run flats and that improves the quality of the run flat ride. Also, tire manufacturers have greatly improved the ride quality of run flat tires over the years and a good quality run flat rides pretty well. Finally, they both said that in some cases, since the suspension is specifically designed for run flats, if you replace them with ordinary tires the ride quality might actually get WORSE. Just sayin'....

 

Personally I don't like run flats. They cost more. MB, BMW in the family came with run flat but now they are on regular tires.
Don't feel anything different.

 

If you change runflats to conventional tires (as I did on my SC430), the ride quality will change, but whether the change is "worse," (as the rep says, above) better, or not much depends on you and how you drive. The sidewalls of a runflat are very, very stiff, so when these sidewalls get replaced with sidewalls with some give, generally the ride will get a bit softer. That's just physics. I found it a big improvement, more comfortable, less harsh, and better handling (cornering) as well.

 

Drove the car today. Runflats were an issue. And had checked to ensure they weren't overinflated. Bummer.