I just loaded v4.41 firmware onto a USB and went through exactly the same process as a normal update. Didn't encounter any issues.I think I will downgrade, I guess its the same process as upgrading?
What content are you guys using to test? I will see if I have it available.
The content I have used mostly is
The Eagles Hell Freezes Over DVD DTS track -- Hardly any bass, especially noticeable on 1st 3 songs.
David Gilmour Live In Pompeii DTS-HD track -- Where did the bass drum go?
Star Wars Episode 2 Blu Ray Chapter 3 (others can be used with same result) DTS-HD -- Almost no bass.
DTS Demo Disc 2016 -- Cymatics track -- The voice over at the start of the track is totally incorrect in terms of steering (confirmed as an issue by Arcam)
There are more, but these are the ones where it is really obvious.
Also, some Atmos music tracks seem incorrect in terms of bass quantity. I tried Roger Waters The Wall, Hans Zimmer and Imagine Dragons (my daughter likes them) and all seemed to have very boomy bass that wasn't there in the past. I don't have an Atmos set up, but this has definitely changed from the previous version.