Goodness. I only looked at the specifications page. The 30 setting is useful, so if buying second hand beware.
Hey, I am pretty sure that dissing my VI is a violation of forum rules!!
As to the settings I have the 30 mV/pa available on my EMP, but I still only use the 10 mV/pa for all condenser mics, including a Senn 8020.
I did, a few years ago, have the side panel changed on my Nagra VI to the later version with the extra USB slot that had the extra power out to power an external drive.