My first impressions (no idea how much of this is due to some psychological phenomenon or another).
Going back to one of my standard presets, there are some differences in how things sound. Better to my ear. Most noticeable was something about the Dynamic Plate Verb--seemed to give a more convincing sense of space.
The preset had the Ventoux as an A+C block. I deleted that and substituted the amp-only Ventoux plus a cab. I tried 2: the princess 1X10 and the Blue Bell 2X12. Default settings. Both were really good. I don't know how to describe it other than they felt
powerful.
Overall I though the quality of general distortion/overdrive is improved. Seemed a lot more harmonic--had that good ringy quality rather than raspy. I tuned my guitar this week so maybe that's part of it.
It also seemed like muted strings sounded a little more like they should.
I tried the new 4-voice chorus. It was cool but I didn't twiddle many knobs and at the defaults it didn't knock my socks off. It's as good as any other chorus model I've tried though. Have to give it some more time.
I tried the dynamic ambience too. Guess I'm not sure what that one is supposed to do. At the defaults it seemed like a very mild reverb. Need to spend some more time with it.
I played through a few of the new factory presets. They sounded pretty decent but I can't really compare them to before. I didn't come across any that sounded harsh and awful the way some in the past have.
I wanted to work in words like "chewy" and "bouncy" and "Amp where I'm at" and stuff but I'm not enough of a tone guy to use those convincingly.
First impression: really cool update.
Apologies to participants on the other forum--I'll probably cut/paste the above over there too.