I have ~700 miles on my 2021 228i GC, I must say the ride is harsh, every ripple / slight payment crack is felt and heard, man hole covers will jar my teeth. Also, the Bridgestone Turanza LS100 run flat tires are so loud that driving about 75 is uncomfortable (225/40 R18 92H).
I live in Florida with great roads, I'm not new to BMWs, understand they favor handling over ride quality, but the harsh ride of this model is surprising. I also have a 2013 135i M-Sport convertible with 18" wheels, without run flats; had the same two women in the back seats of both cars for 2 hours each on the same route, both said without me asking that the 228i ride was rougher and louder than the 135i and they were happy to get out of the 228! That's saying a lot given the cramped back seat, very sporty ride of the 135i
Checked tire pressure, all are set at 35, the iDrive and door card recommend 39, I'll try that but expect raising pressure will make the ride even worse.
What are others experiencing?