I was at the Apple Store getting my old MacBook Pro fixed and the Genius Bar tech told me that there's a way to make your own Fusion drive in Mac OS using Terminal commands. I had no idea! That's pretty fantastic and would definitely clean up my Finder sidebar.
The instructions on how to do that are here. When I get the time to sit down and reformat, I think I'll do this. The OWC Data Doubler in my old MBP has been highly useful but combining it into one drive would just clean things up for me. I like the idea!