Linus replied:
Anyhoo, what can you me about btrfs? I haven't
paid attention, when I
last did, it seemed unfinished. Fedora apparently uses it by default,
should they be? I've been pretty happy with ext{2,3,4}, I don't know
if Ted is still behind those but I've been super happy with how they
handled compat and other stuff.
So did btrfs get done?
I'm not sure how much people use the fancier features, but lots of
people seem to use btrfs in production these days, and the maintenance
team seems responsive and stable. Of the local disk filesystems we
have, I'd pick any of ext4, btrfs and xfs as stable and
well-maintained.
Picking any of those is fine, and the choice would come down to which
distro you use, and _possibly_ whether you want any of the particular
features. But on the whole, most people don't seem to care deeply
about the more intricate features unless they have very specific
use-cases.