I have done some very controlled experiments creating an identical mix across both platforms and over 4 DAW's. On the Mac it was Pro Tools and Logic and on the PC Studio One and Sonar. Panning was L C and R only and all pan laws were set the same. No plugins used, just creating an identical mix sound on the summing buss that was all. The original tracking sessions were stellar
(very well placed mic positions, choice of mics and finest pres available everywhere, great room, excellent band and performance) and the perfect mix was possbile with no plugins being used. Just fader levels only. (Even in mono it sounded amazing)
The playback and comparison listening environment was excellent and I had several people present. On listening to all four it was very evident that there was very very little if not any differences between all four mixes. I was able to create very deep nulls by inverting and adding them together. I was left with the feeling that way things are done on PC or MAC and even over several DAW's, they all do it the same basic way.
Maybe the sound of different DAW's comes into to play the moment you start using their plugins/processing and creating special effects. If you can hear the sound of what you are trying to achieve well in advance in your mind's ear then no matter what DAW or platform you are using I think you are going to get there.