YOu can set those pre/post snapshots automatically and not really pay attention. I think OpenSuse does that by default if you install your root on btrfs. They even have an OS version called MicroOS which does a cool thing with snaphosts. Basically if your system does not boot after update it will revert automatically to previous snapshot, or you can pick a snapshot to boot into manually from grub menu. Bit it is quite a different thing than your usual linux distro as it uses read only root FS.
Pigs