I agree that coach can be noisier as usually have one car steward for 2 or 3 coaches so one would have to find a conductor usually in the diner at night to complain about noise. After 10PM is to be quite time and lights are dimmed to blue night lights. Also on the superliners coach passengers can not use the diner, the diner is for sleeper car passengers only. So coach passengers have only the cafe in the lounge car for food and drink. Remember meals are included in sleeper price. Although on the California Zephyr roomette and bedroom prices are thru the roof. Example Chicago to Sacramento in roomette is $1,225 with a bedroom priced at $2,671 for May 2nd. Remember this is for 2 nights! A lot of days are sold out sleepers, some days show whole train sold out. One note is it unknown how many sleepers they are selling. Usually this train has 3 sleepers and the dorm car that has about 8 roomettes, but with many cars waiting in Beech Grove for maintenance they could be selling just one sleeper or 2 but probably not 3 sleepers. May 5th now shows whole train is sold out! When I rode the California Zephyr in summer of 2021 the train had 3 coaches with last one locked and maybe 12 people per car in 2 coaches. Sleepers were full with some who normally would use coach buying roomettes.