Firstly, I want to supply a link to a archived Behringer 9024 Ultradyne, and technical info about the unit I own since the early 90's and discontinued for many years. But the "technical info", included in this 40-page report is something that you may find interesting to print out as a PDF Mix reference.
I liked this low cost rack unit because it had an automatic mix-adjustment feature (multi-channel compression, that brought everything in the mix alive and "up-front". It worked pretty well and made tedious mixing work easy for this real novice. I hope you enjoy reading the Behringer report in general:
http://www.behringerdownload.de/DSP9024/DSP9024_ENG_Rev_E.pdfOf course, also important is that the sounds being processed should be top notch, which the real-tracks/drums/etc., certainly are. I plan on first processing the new sample tracks and seeing if the results make the sound of the backing tracks more improved by bringing them to the fore.
I still have my Karma, Triton, Motifs, guitars and midi guitars along with these keyboard + effects units, and they record well. And now with Real Track, etc., I'm going to drag it out and see if I can't bring the pro accompanyment, which I love, more to the front of the "live" mix. The unit was also used for broadcast, so I can't wait to see how it affects the already great real tracks/drums and accompanyment. Get my "real track boys" up front and swingin.