I had an event last night, first event in a church at night using my D750+D810 combo, holy shit.
I never use flashes at churches, i have pics with 12000 iso that are so fucking clean, and that D810 shutter sound, it's like the camera is making love to my ears lol, love it.
I was also using the Nikkor 85mm 1.8 and 24mm 2.8 for the fist time, damn good lenses, so sharp even wide open, but the 35mm + 85mm is a perfect combo for these kind of events.
I'm in love with all this new awesome Nikon gear coming from shooting with a couple of 5D MkIII, this is on another level so far.
On a side note, my Sigma 35mm has front focus issues at long distances :/ guess i'll have to buy the calibration tool now.