[Perfectlap]

its not necessarily strictly the size affecting ride quality.
You can have a set of lightweight wheels at 18" which will be
smoother than a much heavier set of 17" and possibly even 16" wheels.

In my experience wheels at 20 pounds and below offer quicker accleration and
their reduced weight allow the springs and shocks to react in a much less severe manner.

THe most important factor in my opinion is the spring rate. You want to have springs hard enough to keep the the car from bottoming out while still allowing shock travel. I think coilovers are the best solution. You can tinker endlessly with the ride height to find the best setup with wheels,tires,suspension. A perfectly setup sportscar will never fell like a Lexus but it can feel pretty darn nice for daily use.