I use always the Radial ProD2 Passive Stereo Direct D.I Box, in connection of my Arrangers..
The differences with simple direct Balance connection (with TRS cables), and the connection with Radial ProD2 (or with a good Passive D.I Box), is that:

1) With Radial D.I (and with a good D.I Box also) the signal is transformed to MIC connection, (with two XLR cables), and we can to use the Gain of Microphone Pre Amp of console, without distortion, and the good way to transformed to MIC the signal is with a good D.I Box..
2) This D.I is specifically designed for Keyboards, Drum Machines, Samplers, etc, able to handle huge transients without choking..
3) With Radial ProD2, we have a smooth, warm sound, much more better than, Line direct connection or Balanced connection, eliminating also hum and buzz caused by ground loops.
4) Becouse the Radial ProD2, is Passive D.I, with two high performance transformers, it does not need Phantom Power (48v), like the Active D.I,s..
5) The difference of Balanced (TRS) connector, and transformed MIC of D.I is that in a Balanced (with TRS cables), the signal remain Line, although is (Line Balanced)...

If you go through the DI box to a suitable mic preamp, you can also benefit from the tonal colour the preamp offers
(Sound on Sound magazine)..
http://www.soundonsound.com/sound-advice/q-there-any-point-di-ing-keyboards

I am use always the Radial ProD2, with my Audya 76, Audya 5, and Pa3x also although Pa3x has Balanced Output...