I have enough material from work level stuff to post this quick comparison. Not to show which one is “better,” but to just simply show the image rendering and bokeh that one can get with these two setups.
The idea for this came from the Lunar New Year at Stone Mountain, as I wanted to capture the hanging lanterns and really knock out the background and distracting foreground elements (wires around the stage). The first set was when I lugged the heavy D700 and 200mm f/2 combo. The second time was me using the R8 with the Nikon 105mm f/1.4 with a simple dummy adapter and giving myself a challenge with manually focusing the thing.
Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR

Nikon D700 + Nikon 200mm f/2 VR
Canon R8 + Nikon 105mm f/1.4E (all images manual focus)

Canon R8 + Nikon 105mm f/1.4E

Canon R8 + Nikon 105mm f/1.4E

Canon R8 + Nikon 105mm f/1.4E

Canon R8 + Nikon 105mm f/1.4E

Canon R8 + Nikon 105mm f/1.4E

Canon R8 + Nikon 105mm f/1.4E
Both setups are very nice for different reasons. The native D700 + 200mm combo produces such great RAW files that you can take into any direction color wise, and the out of focus elements are definitely largest. The R8 + 105mm combo is light, but obviously requires two hands to manually focus. Since the lens is always wide open at f/1.4, the DOF is quite shallow and takes practice to capture performers in motion. The Canon shots are pretty much out of camera, with no WB adjustment and only minor exp adjustment in post. That is one of the great things about the Canon system for when you don’t have the time to really edit each and every image (like me). The bokeh and out of focus elements are more cat’s eye/lemon drops and curve around the subject, which is a look I personally like. If I ever get my hands on a 135mm Plena and Nikon mirrorless system, I’ll have to see if that type of rendering is the way of the future!