I fit directly into this category. I work at an “all avid, all PC” facility. I bring my macbook pro to work every day. Why? Because I have customized my laptop to death, to the extent that I cannot replicate it on a stock machine. Little things like having dragon dictate installed, meaning that I never ‘type’ log notes in, I just say them into the computer — makes me able to work longer without breaks. And my wrist thanks me.
My bosses are aware of my improved efficiency but don’t know the details, other than the fact that I churn through footage faster than my coworkers. They obviously praise the effort, but sometimes it creates an interesting situation that might be worth exploring on its own one day: Last week I was asked to withhold some of my logging data because it would “create an unfair advantage to my team.” I guess that’s an office politics matter, but bottom line: these small customizations, when added up, give me a noticeable advantage against the worker who relies on the locked-down work machine, which has zero extras besides a retail copy of Avid.
So in conclusion — I think that ANY worker who brings in their laptop is going to be more efficient. The majority of people who do such a thing just also happen to buy macs.