Quote Originally Posted by liam View Post
You're assuming performance is the raison d'etre for btrfs, but the big gain would be in the snapshotting. You would no longer have unrecoverable systems due updates. You would be able to safely update your system from release to release without doing a reinstall (this doesn't mean the update would work but it would mean that it would be safe). These are ease of use features that would be fantastic to have and that's ignoring the data assurances it provides.
Don't we already have snapshots courtesy of LVM? OpenSUSE plans to introduce a tool called snapper with their next release that does everything you want it to (including snapshot before installs, updates and timed snapshots and the ability to recover even a single file) with Btrfs, but a Google Summer of Code project is supposed to "Add ext4 snapshots support to snapper". If the project was successful, it might be offering everything you're looking for.