Making something the default is a high bar to clear.  There needs to be a compelling reason why?  The things listed in the proposal may be nice for some people, but the uninformed masses don't care.  Further complicating the matter is that Redhat deprecated BTRFS.  That to me raises a big red flag that needs to be addressed. 

===> You need to clearly identify what gave Redhat heartburn and identify what has changed to make you believe those issues have been addressed. 

Another thing that is particularly troubling is I can't find where it is stated that there is a production release of BTRFS.  I've seen statements that it is "testing in production" - whatever that means... and that it has been deployed on "millions of servers" - but the only statement as to code stability just says that "The Btrfs code base is under heavy development."  I can't find an official statement from the project that there has ever been a production release.  This is concerning to me because when I reported problems in the past I was told basically, "silly you... BTRFS should only be used in non-critical systems - if you're concerned about stability you shouldn't be running it." 

===> If we are considering BTRFS as a default, at a bare minimum there should be an official production release from the project.