Sorry, but I just don't understand what the purpose is, and it isn't stated in the thread linked -- other than a few
... (maybe) benchmarks that don't cover many real-world use cases.
With CFQ, an high disk-IO task will block every other process on the system from getting any time. This can be a big file cp, but I see it most often when writing to slow USB thumb drives... Queue up a copy/rsync/etc. of a few GBytes of data to a slow thumb drive, and after your RAM/buffer cache is filled, your system will be almost completely unresponsive.
Change your scheduler from CFQ to deadline and your system will spring back to life. I don't specifically know that BFQ does any better, but it couldn't possibly be worse... CFQ is crap.