Let's say I have a RB433 that I have setup already, I performed a system backup, could I restore it to the RB433AH without problems?

Or let's say I have a system backup of RB433AH and it fails, can I restore to another RB433AH? I guess my concerns are mac addresses of hardware not being the same with the restore/backups.

Thoughts?

Thank you in advance for the help.

backup will restore the same device just fine.
a different device will not be completely restored. even same model.

When restoring from a backup, the interface settings will not be correctly assigned on new hardware, therefore after a restore anything that previously referred to an interface or was hard coded to a MAC address on the RB will need checking and correcting as necessary. Backup/restore was designed to enable fast restoration of old settings onto the same hardware it was backed up from. In those cases, as the hardware is still identical, the restore does not 'mess up' any of the interfaces and it works very well for fast restores. Especially when testing new ideas.

For restoring to new or different hardware use the 'export' command to generate a text file which then can be used as a script to load a new router with the old settings.

After exporting, I run through the generated text with a text editor to 'clean it up', add comments and thus make it more readable.

As with all backup or disaster recovery regimes, creating an excellent and reliable backup of your system is not enough. You also need to run a test of restoring onto new hardware to see what would happen for when the whole lot comes crashing down around your ears. Which it will do when you least want it to.