This is an old revision of the document!
BTRFS is working well at the moment on a single disk, like for a home user. For multiple disks the RAID implementation requires too much babysitting. Even RAID1 is a nightmare in some scenarios, where the disks can become out of balance and all sorts of ridiculous things with no feedback to the end user anything is wrong. The development of BTRFS is progressing, but it is slow, so for now its suited for home use on a single disk, you dont have to baby it all that much and it works well.
If you want some sort of mirror setup over multiple disks, use zfs for now instead. One day we will have BTRFS working well, but not today. Unless you really know what you are doing, RAID on btrfs is not for you.