As a project, I play with an acoustic guitar, a small semimodular synth, and a loop pedal. I also play sometimes with a friend who has a modular synth and me with semimodular + looper.
The alt bus is the feature I was looking for the most, to be able to allways choose whether to send a channel to record with the looper. Allows us to play live with several channels and I can just pick one or two to record and loop while the others are left unchanged.
The sound quality is good enough for recording, I'll maybe edit this feedback once it will be tried in a live setting.
It's packed with features. Compressors for the mono channels do an okayish job if you don't need real control over it. The 3-band EQs are fine. Double AUX send: one AUX send and one FX send, both with returns, offer quite a bit of wiring options.
I was pleasantly surprised by the quality of the built-in FX unit. I mostly used reverb so far, and it's great. I also didn't expect it, but you have some degree of control over each effect by being able to tune one or two parameters per effect.
In terms of outputs, I got surprised by the fact the main outputs are only XLR cables, but after a second thought it doesn't bother me at home since I record from USB and send to my home speakers via RCA, and for a live setting having an XLR output is the better option.
I can't go over all the features, there are too much, here's a list of which I use and how I use them
ALT 3/4 -> to send in the looper, coming back in a stereo channel
Builtin effect unit, mainly for reverb, with option to send the effects into the alt 3/4 (to have effects inside the looper, however the effects bleed into it) or only to main mix (with zero effect in the looper and therefore zero bleed)
Solo mode with prefader listen (to prepare a new modular synth voice before sending it into the mix for an improv situation)
Panning with synth voices for even more trippy loops.
All the connectivity: Ctrl Room, main mix, phones, RCA out, usb for recording...etc...
Compressor for my acoustic guitar channel when I use it, EQ for everything to try and keep the mix clean.
The usb out works in Linux, I record in Ardour (in case it helps someone, since some usb codecs are proprietary and don't work properly with Jack).
It is the first time I ever own or use a mixer, and I didn't have much problems figuring things out. However I have a scientific background, I did study some electronics on my own, and I did quite a bit of research before buying this unit because I wanted to be sure I had a good way to use my looper with it, all of this together may have helped to figure things down. The manual is nice and concise, however it's not a tutorial and doesn't explain anything: it only tells you what does what and never tells you how to use what. (There are some wiring examples for various settings though. Didn't check them since none really apply to my case).
With all this considered, it still felt a bit impressive the first time I sat in front of it haha!
Overall I'm super happy of this purchase. I'm getting everything I needed and a bit more for a price that is more than fair given all the features.
