Unless you crave a marshmellow-soft ride—which frankly neither wheel will give you with the Model 3's sporty suspension setup—the cornering authority of the 19" wheels feels really grippy and confidence-inspiring. It feels safer than cars that roll a lot and threaten to lose traction. And it really doesn't feel harsh. Feels sporty.
I used to always choose small, practical wheels. But 2700 miles on the sport wheels have made me a fan.
Edmunds felt the same way in
this video comparison of the WHEEL/TIRE COMBINATIONS when they swapped the wheels and tires and did cornering, stopping, and acceleration tests. The got better cornering (0.85->0.93 gees), stopping (133->128 feet) and even 0-60 acceleration (53->5.1 secs).
By the way, notice that both setups did much better than Consumer Report's recent braking tests.