I'm just testing the entermice with the SEGA twister. (Not the full functionality, only plain one button games like Cybernoid I) It works like a charm. And sega contollers are very good for most of the EP games ...
As far as I remember, somebody wrote a joystick tester program, a really full featured and "graphical" one ...
Maybe that should be extended to test the full functionality of the sega thing, too ...