Flew ORD-KOA on a 789 in 22E. Despite being a middle seat, the design of the seat made it comfortable although I could not make it lean back as much as I thought I would be able to. Personal item space in front of me was nice and wide but was not great on clearance which looked to be no more than 6 inches. My personal item, a backpack, would not fit under the seat ahead of me (would not fit in economy on a Max9 either but fit with extra room in economy in a 757). There was no amenity kit and there was a blanket.
2 meals were served during this ~8 hour trip, I did not get the meal choice I wanted for the first meal as they were out of the protein dish by the time they got to me. The attendants did bring up a cold Chicken Quinoa dish from economy that, to me, was superior to the Cauliflower salad option that was the only premium choice left for 22E. The second meal was served from back to front so row 20 drew the short straw. I do not recall getting asked to reserve a meal.