The first Civity that I rode an was a 331. It was also on pretty reliable track, - Doncaster to Leeds yet I (and the two others also trying them out for the first time) thought that they were jittery and poorly damped.
My main experience of 331's is Doncaster to Bentley, they're somewhat twitchy and jerky on the points off Platform 4 in the same places where the 321's used to roll and flop about, so they've replaced one slightly irritating tendency with another.
Came back from Sheffield to Doncaster on a 195 on Easter Sunday, the stopper service too. The acceleration was quite impressive compared to the 150's I've usually had on this service, but like the 331 there's quite a bit of noise - random whirrs and clangs - from the aircon.
First time I went on them - Chesterfield to Sheffield early 2020 - I found the noise they made when coasting to be quite bad (the approach to Dronfield especially), worse than when they were accelerating, and the passenger door windows had quite bad condensation on them. Don't remember either the other week, but that's maybe due to the Sheffield-Doncaster service's shorter and lower speed runs between stations, and the warmer weather.