The fsck for btrfs is still not quite there. If you are using multiple disks with btrfs's mirroring/checksums, hopefully you won't get hit by HDD hiccups leading to metadata corruptions which btrfs's fsck can't yet handle. I certainly wouldn't recommend running btrfs on a single HDD/SSD unless you are doing frequent backups and don't mind losing state between backups if you get unlucky.

Also, please note that btrfs snapshots != backups. They will not save you in case of device failure. Checksums also won't help you if there are kernel bugs.