Here are the differences:
The snapshot utility backs up everything, including the drivers, and is available only on SecurePlatform.
Snapshot can be used to backup both your firewall and management modules.
The disadvantages of this utility are that the generated file is very big, and can only be restored to the same device, and exactly the same state (same OS, same Check Point version, same patch level).
The backup utility backs up your Check Point configuration and your networking/OS system parameters (such as routing), and it is only available on SecurePlatform.
The backup utility can be used to backup both your firewall and management modules.
The resulting file will be smaller than the one generated by snapshot, but still pretty big.
Backup does not include the drivers, and can be restored to different machine (as opposed to snapshot, which cannot). However, it is recommended using the backup for restore to the same machine since it includes information such as MAC addresses of the NIC interfaces. (Note: Since MAC address gets restored as well, customers should be advised prior to restoring to make a note of original MAC on the new box, so it can be changed later on.) You only can restore it to the same OS, same Check Point version and patch level.
Database Revision Control:
This utility creates a version of your current policies, object database, IPS updates, etc. It is useful for minor changes or edits that you perform in SmartDashboard. It cannot be used to restore your system in case of failure.
Migrate Export (Upgrade Export):
'upgrade_export' tool backs up all Check Point configurations, independent of hardware, OS or Check Point version, but does not include OS information.
You can use this utility to backup Check Point configuration on the management station.
If you change the Check Point version you can only go up, in other words you can upgrade not downgrade.
The file will be much smaller (depending on the size of your policy), and if the system is not running on a highly loaded CPU, you can do a backup on a live system without interruption of the services.
This utility can be used only on command line and cannot be scheduled.