Just noticed this article, benchmarking linux games running on Ubuntu against the same linux games running on PC-BSD with the linux ABI:
The results might surprise some. It would appear that FreeBSD is more efficient at driving the video hardware than linux. Enough so to mask the overhead of the linux translation by the ABI, and still come out the winner.
Who knows, with enough positive news such as this, FreeBSD may actually get some of the credit it deserves, and draw people in from the linux crowd. As a FreeBSD user, I am always happy to see good news like this.