"while Ubuntu 10.04 is using Linux 2.6.32"
For BTRFS it should be nice to test it with its latest code, or at least with 2.6.33-rc8. It's an experimental FS so its important to see its latest improvements. As always phoronix is too ubuntu focus.
Anyway good article, and WOW!! nice BTRFS perfomance!, a compressed btrfs partition results should be interesting to see too!!