I am using the RB750Gr2 for now nearly 7 years and the thought has crossed my mind what do I do when this hits the dust. No doubt it will keep going because it has been such a great device but I am planning to have a another similar Mikrotik device ready with my current config loaded as a back up should my router eventually fail. The question I have is do I buy the RB750Gr3 or wait for a refresh. Are there any plans to release a new MIPS based device to refresh the RB750? If I got with the RB750Gr3, then is it as simple as exporting my settings into script file from Gr2 and importing it into the Gr3?

You WON'T restore binary backup in the newer model. You should do exports in text form with "/export file=...." command
Haveing configuration in that version you can easily apply it to the new device despite the model if only it has similar set of interfaces.

Yes i figured a binary back up would not work as they're different models. I am mainly concerned with my dhcp static addresses, firewall rules and address lists. I guess there are no plans for hex refresh around the corner?

Use /export to save all that information.