This really is a great all in one solution for keyboard players. Both for playing live and in the studio.
I use it as the heart of my 3 keyboard rig in our rehearsal space. The monitor out is great for when i want to play all three keyboards with headphones, not disturbing the others. This merging cable (193901) does the job perfectly!
For most of the time it is only used as a submixer but it has a lot of tricks up its sleeve. For example, when recording you only need a computer and a usb cable and you're all set.