I use Carbon Clone Copier, on an external drives.
If my system or project drive fail, I can swap drives and keep working.
I just have to be more diligent at backing up!
Let me clarify, there is a standalone Aria app, and an Aria AU plugin.
Make sure you're using the Aria player plugin on an audio instrument channel.
I've used their Big band instrument for several years wit no problems.
I'm using the original silver-face Apollo over FW800, with no problems.
Be aware that there is an optional Thunderbolt plug-in circuit board available when you upgrade machines.
The performance boost comes when you move to TB.
More info here.
https://help.uaudio.com/hc/en-us/articles/215262223