Windows 7 x64 install time
Lets begin with a simple test: Windows 7 x64 installation time (phase1):
I included EXT4 also scores to have a reference. As you can see, with cache=none BTRFS is quite slow; however, start using some cache (cache=writeback) and installation time returns to normal values.
Anyway, I did not expect extreme differences in this synchronized-write bound test. Lets see if a more specific test shows some greater variations.