Hi @Martin_Raska
You can think about Gaia backup as a general tool that will backup all product related content that is running on the specified machine.
Products can be - Os, FW, VPN, MGMT/MDS, Smart view, etc.., You can see more information here.
When you execute Gaia backup on an MDS machine it will run the mds_backup tool for you (with basic parameters) in addition to all other applicable application that relevant for that backup execution.
you can think about running the mds_backup as a subset of all the possible information that you can collect,
The question is what is your restore procedure -
In case you are interested only in the MDS content, you can manually use this tool.
If you want/need to save additional information from the machine, you should use Gaia backup
For more information regarding the different backup options, click here
Thanks,
Gregory