I work in film and commercial production, and the landscape there is 95% Apple on the producer / executive side, 80% Apple in the design / DTP world, and still very much Apple dominant in the edit suites, although I've seen a few places make the switch to more prosumer editorial solutions - Premiere on a PC. Editors in general are a crusty old guard that don't like change. I knew one that was still using an OS 9 machine because Media 100 had plugins that he liked. Editing isn't heavy on GPU, and is for more reliant on CPU and drive speed.
You'd be hard pressed to find a PC based audio house.
The 3d and composting world is nearly all PC, and that's almost all based on GPU availability.
My work straddles the line, so everything that isn't Houdini a simulation, Nuke comp or Redshift render is done on a Mac - all of the day to day tasks just work so much better in the Apple world (for me). Everything design, edit and audio based, all Mac.