I had been wondering about this myself, for some reason I was under the impression that the BFS was no longer being maintained.

It turns out there is an up-to-date package for Ubuntu (I'm running 10.10) as well: http://launchpad.net/~chogydan/+archive/ppa

I thought I'd try it out as the installation was much more straightforward than I'd expected.

'uname -r' now reveals "2.6.35-22ck-generic" and, while this is just my subjective assessment, a few of the quirks I had noticed before on my own system where things would get sluggish when switching between apps / opening closing apps while running things that read/write to the disk, seem to have been ironed out.

I would love to test this in a more empirical manner, as I can now boot into either kernel to do comparisons, but I don't know of any software that would allow me to benchmark performance in a way that is sensitive to the optimizations the BFS allegedly implements.