The Look

>Wow, love the new overall design, looks even a bit darker which is awesome in night sessions

You have three more levels of grey/contrast in Preferences. Try those as well.

It works fine.
I love the new design.

The wrench tool is gone, replaced by a little gear wheel, ok I have to adapt, after 100 years I have to learn new...

The Loopback indicator is bigger and is also on the output channel at the bottom and at the gearwheel button and on the input channel on top.
That is fine. 3 signal instead of one at good places.

The orange dot next to the gear wheel is ON whenever a function inside is ON, MS proc. or phase invert.

And zooming into it at every place is a great feature.

The input channels have some more visual aids :

The mic inputs have a little microphone symbol at the top it turns orange when phantom power is ON. Wonderful.

The analog inputs (Babyface Pro and UCX ll) have a little guitar it turns orange when the INSTR button is ON.
This function is available in the UCX ll interface but not in the Babyface Pro. Will the interface recognize an instrument signal and turn the guitar symbol orange ? It could be orange at input level setting -10dBV (after beta testing...?).

The grey high contrast setting let you see the selected submix better.  This will be more prominent on the new MabookPro Nano displays.

AND : The global Solo and Mute button have indicator for "active" It shows OFF, ON and active ! Right ?

The big FX button is replaced by 2 buttons "show" and "hide" and a %-display. This saves some space, that's good.

All these visual features are implemented softly and useful, no problem to adapt for old bags like me.

The only request : 2-finger fader move - reverse it, it is still the wrong way.

Bravo and thank you very much !

On macOS, holding shift while using the mouse scroll wheel over a fader reverses the direction of movement here, though this seems to be the case for classic Totalmix as well.

With shift down it moves in the (for me) correct direction, opposite of whatever the system setting is for "Natural scrolling". In any case it should be the same direction whether doing fine adjustments or not?

But I really wish you would take the opportunity and instead support horizontal scrolling when shift is down, and use another modifier for fine adjustments. Much more useful when navigating the mixer, imo.

There also seems to be an issue when CMD zooming all the way out, the channels start scrolling sideways.

Otherwise it looks awesome, great job!

wow, seems nice !

just a question : of course all workspaces / snaphots, fx, various settings are kept alive (the same) without doing anything ? and since mc, you said, we can switch "between the new and the old design any time", all theses setting will be reflected doing so ??

Very well done! I didn't think it would happen so quickly. I'm already looking forward to the Windows version. :-)

all the UX features mentioned in the OP are awesome, but the overall "flat" look is awful as of now,
I do understand freely scalable GUI requires some design compromises, but washed out colours and lack of any shadows or depth makes it less synoptic,
I'll thoroughly test it within few days, but one of the features I missed in TotalMix FX was colour-coded channels (not just channel names) that would make the mixer maybe too much "rainbowy" but easy to understand and see,
I can guess TotalMix FX looks fairly dated nowadays (and I do remember previous TotalMix as well), but I'd encourage RME team to spend bit more time on minor design tweaks to make this truly awesome, maybe I'll try to make some mockups to better illustrate what I mean with changes

Yes and yes.

They do change in hardware, but the label is not refreshed. Will be fixed in next beta.

alright, so some more initial thoughts:
1) scaling is amazing because I can finally fit entire I/O of Madiface XT II on 1440p screen
2) it might be useful to have option of independent horizontal/vertical scaling (for ex. narrow but tall channels) but not a dealbreaker
3) control section on right is not scaling, is that intentional?
4) colored channels are so useful, now to make it perfect TotalMix could color assigned hardware inputs and software playback channels AND show correct user-assigned names (of the selected bottom output color+name) in them:

Beta 3 is available via the link in the first post. Changes:

- RefLevel labels did not change when loading a different Snapshot or changing the RefLevel at the unit

- Mackie Control: Trim markers were not redrawn correctly

- Reverb Presets and Factory: removed Echo ones and replaced with Reverb ones

I am on Win so I cannot try it. And maybe in real work I would feel it differently....

It seems to me that "knobs", or better said that what knobs has replaced, could be improved so that there is indication of endpoint (current possition). In current state, it is not (at first sight) obvious, where the current position is (which end of arc)....

IMHO, a small mark (tick) at the actual position would make it clear. The tick could be on inner part of arc, or outer one. Or the best could be on the both sides.

EDIT.
Either way, I am looking forward to Win version. :-)

Looks great!
The "D" of Dynamics in CR-Section and Outputs seems to be randomly cut-off. Re-sizing the channel fixes it.
Picture in post no. 19 shows it.

With PFL button do you mean the CUE buttons ?

One more visual nitpick:
The meter background changes color slightly as the signal crosses -75dB. Looks a bit erratic/weird.

RME is the best! My Fireface UFX has been around for almost 15 years! I like the GUI to stay unchanged for a long time; it's very intuitive, but a refresh is always welcome if it includes under-the-hood improvements. This is almost what I always imagined, especially with the color channels and high contrast. The only thing that catches my attention is that it consumes almost double the CPU. On an M1 MacBook, the old version peaks at 13%, while the new one reaches 20%. That's why I usually close it when mixing.
The good thing is that the iPad versions are still supported, even one running iOS 9.

Not at all. You seem to have missed that here the level meters are removed when no signal is present. Quite helpful in overview and de-cluttering the UI.

I get it, that’s why I included the -75dB.
Then maybe the threshold could be lower than that or set by user?
No big deal, but in my case the meters flicker on and off if it‘s not dead quiet in the live room. Happy anyway with v2, feel free to ignore.

Can't wait for it to come for Win. it looks amazing. Good job!

Go to settings and activate "Always init devices with TotalMix FX setting"

Unclear. Does the expected Snapshot state load? If so does it help to save it one more time (aka refesh)?

I get both messages, but the snapshot loads normally; also the indicator in the Control Strip does not blink. Saved the snapshot again, but still the same behaviour. After activating "Always init devices with TotalMix FX setting", I did not get the messages for one startup, but then they came back.

I found another basic feature missing - when renaming channels - either in totalmix gui or channel layout window - COPY & PASTE doesn't work in those rename boxes

Works for us. You're on beta 4? Which interface? Sure all ARC USB related settings match?