Pretty cool stuff! While I don't have one of these (yet), I do have an Apple IIe Card installed in my Macintosh LC III. One of the first examples of (hardware-based) virtualization I'm aware of, allowing you to run Apple IIe software within Mac OS. When I was in middle school, one of the computer labs had all of its Macintosh LC IIs fitted with these cards, and had 5.25" disk drives sitting next to them. I remember using them that way once or twice, but used them in Mac mode the rest of the time (including when we played Oregon Trail).
-Adam