Hmm, do not find any difference regarding speed in my case.
Actually, I'm pretty fed up with Bridge and ACR:
1. Bridge doesn't allow me to open all of my nef files (even if they're from the same "serie" of pictures), some tiff I get to open in ACR (via Bridge), others not. Seems pretty unstable to me.
2. In ACR we don't get to see the actual change when adjusting things like colorspace and mp - in camera preferences in ACR. Before we could see if the files got any burned out highlights when going from ProPhoto RGB to sRGB while adjusting in ACR. If we change mp from original (45 with D850) to 5 mp, we don't see any change in actual size - if I want to see how sharpening adds to the 5mp file, I have to send it to PS, because when in ACR we still have the original size when zooming in at 100%.
Considering using Capture NX- D as a raw converter and find another solution to use instead of PS.