2016 Avalon Limited Rough Ride

Love most everything about my 2016 Avalon Limited except the rough ride. 
You can feel most every bump, crack and sewer/manhole cover on the road.

I know Toyota gave this trim model a "sportier" suspension with 
225/18/45 skinny tires on 18 inch wheels- rather than the fatter 
215/17/55 on 17 inch wheels on the lower trim models.

It's getting to be tire time and I wonder if it might be worth trying a 
tire/wheel package in the smaller size.

Would the taller 55 sidewalls absorb road bumps better? Any problems 
with transmission shift points, speedo readings, any of the electronic 
stuff, etc.?

--
Teacher: Why are you late?
Student: Class started before I got here...