Analyzing what you have so far, BTRFS is quite cool, don't you think? However, we have not yet exhausted the wealth of goodness that it has to offer. Snapshots can be used as read only or read/write copies of data. The reality is that there is no need to copy data as it is effectively linked until it changes in one of the locations. In this way, a snapshot of a large filesystem can be taken instantly. You can use snapshots in the following ways:
As part of a backup solution where you may be concerned with open files affecting the backup, the snapshot will be created as read only and subsequently you will implement a backup of the snapshot. In this way, the backup will be of the host filesystem at the point in time that the snapshot was created.
Snapshots can be useful where you know many files will change in a structure and you may want to restore the original files quickly. Perhaps where you are working with scripts to modify many files, you can easily revert to the...