Using Btrfs snapshots for online backup?

I am looking for operational experiences, thoughts, or alternatives to using btrfs' snapshotting to perform online backups of a system that will be under continuous write load. There are several files that will be facing appends and rename(2)'s, so I can't just rsync and call it a day (the rename(2)'s would interfere with resuming a failed rsync...)

Thanks for your thoughts!