1. Yup, sure does! You can choose between having the system volume control affect the main output or a specific headphone output.
2. No strange issues in Zoom or Discord specifically, but see below...
3. Haven't used the optical outs yet. I use a pair of Output Frontiers with a Presonus T10 sub. I'm trying to find a good solution to add another 4 channels over ADAT / SMUX in and out, probably will end up with a Focusrite Clarett OctoPre.
4. I think it's really useful, I rarely open Apogee Control and I use the touchscreen instead most of the time.
Generally, I really like it. It replaced a Presonus Clarett 4Pre (with a 2-day detour trying out an Apogee Duet) and I feel like the sound improvement was drastic. Before the Presonus I had a UAD Apollo X4, and an 8P before that, but I went away from the UAD platform after getting frustrated about how much time it took for them to support new OS' and how slow they were at getting Apple Silicon support, so I wanted to get something that was class complaint. It also has onboard DSP for some mic preamp, compressor and EQ emulations that sound really good (and they work on the optical ins now, too.) The control plugin is good, too, but the direct integration with Logic like the Ensemble has isn't out yet.
All that said, it has one big bug. There's an ApogeeGlue process that seems to have a runaway, and the longer you have it up the more CPU % it consumes, until it craps out - which for me takes about 36hrs. When it does things that try to use audio get very weird and freezy, the system volume control starts to lag, and eventually it stops being able to pass audio altogether. To fix it you need to restart the Symphony, and if you do that while it's crapped out it'll freeze your whole system for about five minutes. There are multiple reports of the same on GearSpace, and it seems like the people with Apple Silicon Macs generally can resolve it by re-arranging how things are plugged in to get the Symphony on a dedicated USB bus. On my Intel iMac the controller puts devices on buses dynamically, and it won't go on a bus by itself. Right now I'm just hoping when I get my Mac Studio the issue doesn't follow me.
Apogee's aware of the CPU runaway issue with ApogeeGlue but haven't connected it to the freezing, and are still in the "we need engineering to look at it" stage. I've sent them a bunch of process dumps, logs, etc. and I'm staying on them as much as I can without feeling like I'm being annoying. I'm sure they'll fix it eventually, but no idea how long it'll be.
Huge thanks for a detailed reply!
I'm kind of in the same place with UAD. I'm not an audio person or a heavy plugin user (one channel strip, really). I just need to get my live spoken audio sounding good, and I want to monitor with the effects on, so I know exactly what's going out to people paying to hear me. I think it's not an accident that Apple keynotes and promo materials consistently show Apogee gear, and UADs software is a big part of that.
I'm going to keep an eye on this while figuring out what else I want to do. I've actually considered the Duet 3 for what I do, since the channel strip is probably fine for me (no gate, but I think I can live without it on a dynamic mic). Though, I'm not sure how they made such an ugly dock for a nice-looking device, and the Symphony has optical out that I think can be adapted easily to feed AES to some Genelecs (if I got 8330s).
Follow up question: does sleep on the Mac work with Symphony Desktop (and not require power cycling the interface after wake)?
Thanks again!