I use my Nord G2 as best friend with my OT.
And the G2 can be used as a flexible midi processor if you want.
What i use often is using the OT crossfader (CC48) to control a morph-group in the G2 (so i can change all kinds of parameters in the G2 with the crossfader). I even made it so that the G2 reacts on Scene changes and i can set (in the G2) on wich scenes the crossfaders works or not.
Also i did this: OT as Polyphonic sampler (8 voices) with Nord G2