I've been using the Nuendo control room solely for my monitor control needs since Nuendo 3.2.1
It is great.
These days I have the RME ADI-8 QS as the last step before my 6 speakers (5.1)
I use the QS's remote controller set so that when the Nuendo control room level is at 0, I have 85dBc calibration.
This means some digital attenuation on the QS, but not much.
The QS's remote have a recall setting so I can always recall the perfect calibration.
It also has a (panic) mute if something should go wrong. I've never used that mute function
The control room in Nuendo is one of the most important features we got IMHO, and I love it.
Nuendo 6.0.x, MAC pro, Macbook Pro 17" i7, RME MADIe, RME Babyface, Artist Mix, Control and Transport, CC121.