If you record a track through your digital mixer into your DAW, unless you route it back to your digital mixer, you are basically just using the mixer as a controller and input device. By having everything route back to the mixer, the headphone, outputs to your monitors and effects of the mixer can now be used. Not to mention the automation (with the exception of the 01V96) on the mixer can be used.

Many use the DAW mixer as a sub mixer and then put everything through the digital mixer. When I was in Nashville and I went to several different studios, those with digital mixers did it this way.

The problem we all face with digital mixers is this. When you route everything back to the digital mixer, each track in your DAW has to be routed to a different bus. (Normally you would assign Bus 1 to your master fader) Then you have to route everything back to the DAW again.
The problem comes when you hear the mix through the master fader and the signal through the tracks at the same time. So now when you are tracking, you have to disable the master fader, so the music won't be going through your speakers twice. Then when you want to put all the tracks to a master stereo track, you have to disable the tracks and leave the master track enabled. I have found this work flow to be very annoying. I heard on SX 2.0 you have mono busses instead of the stereo busses in 1.6 (On my digital mixer you have to pan channel 1 {Cubase mixer- bus 2} hard left and channel 2 {Cubase mixer- bus 2} hard right. But then I find when I pan on my DAW the signal does not pan properly. Does anyone else have this problem?

Also have you found a way to have your work flow with master fader and track audio to flow better than what I discussed. \:\(