I just loaded the Nvidia 520 Proprietary Tested driver.
And...
What a mess.
It broke - Everything.
I ended up falling back to display defaults and Nouveau.
I tried three times, all unsuccessful.
It took me about an hour to fix everything.
I then tested the 515 and 520 Proprietary and had slightly better results... But they both had issues. Conky would no longer display, for one...
I reverted the the 510 Proprietary that I have been using until now.
But as it stands... I do not recommend the 520 Proprietary Tested Driver.