One thing BTFRS has, and EXT4 will never have, is check summed data. And this is very important to have even for desktop daily use.
We can have "Bit Rot" conditions on EXT4, XFS and other file systems, but not on BTRFS (or ZFS, HAMMER) as they are also fully checked summed.
I'll take check summed data any time over EXT4 inferior data protection. Please consider this for future releases.