Bought used one recently, will plug it to my master buss chain before my sound card. Ableton outputs to x desk and monitoring thru the headphone back as well as mix buss.
I like the idea that you can blend dry and wet signal for your mix buss in the routing with one knob, sounds like a big feature I need to try.
I keep my patchbay for my instruments and pre amps of choice connected to the x desk.
Only tested the sound with my rytm so far I need more testing and more recordings.