This thing works GREAT.
The level issues I was having with the MOTU are gone, and creating an aggregate device in OSX to use both the MOTU and this at the same time in Reaper took all of 2 minutes. Out of the box with the input at noon, my DI peaks right around -3db and sounds spot on when I send it back out to my Mark V.
Here's a wet Axe-Fx track and a DI from the Apogee:
So my recording/reamp chain is:
Guitar -> Radial Pro DI
---- Radial dry XLR out to the Apogee
---- Radial wet/thru out to the Axe-Fx
------- Axe-Fx DI via MOTU out to Reaper
------- Radial DI via Apogee One out to Reaper
---------- Reaper Radial DI track via MOTU to the Radial JCR > Mark V
---------- Reaper Axe-Fx DI track via MOTU to the Axe-Fx
The only time I would have to swap cables would be to change the source I listen to while tracking from the Axe-Fx to the Mark V, and I can low-volume record the stuff with the Fractal and then send the DI to the cranked Mesa when it's a more volume-friendly time.
Awesome setup dude. Very jealous.