Speed up iMac 2013 is this the right way?

[dnanian]

You should be able to do that. You'd create a "Sandbox - shared users" on the SSD. That'll copy everything but the contents of /Users to the SSD.

Time Machine will likely recopy everything from both drives if you do this..but I believe it will run normally after. Note that you'll want to back up the main drive, for the most part - you'd going to use this just like a regular Sandbox.

Hope that helps!