Two weeks in (about 14 hours on indoor courts) and my Y-3 Adizero Cybersonic 2 is a legit upgrade from the Ubersonic 4 and 5 that I previously owned. I sized up a half (same as Ubersonic). Break-in was basically nothing. On court they feel steadier on lateral moves with more pop on the forefoot. Breathability and heel lock are about the same (which is good). They’re a touch heavier on paper but I'm not feeling it in play. I coach pickleball and these hold up great. Plus the look of these Y-3s gets compliments. If you’re between sizes I'd suggest going a half-size up. Overall these are stable, springy, clean fit and exactly what I wanted.