Sort of ruins USB for HID devices on classic Amiga's.
Well, I wouldn't be so pessimistic. Enables a lot more than three button mice, but also mice with even more buttons, scrollwheels and whatnot. Multimedia keyboards. Also USB tablets and the nifty 3D space navigator with three rotational and shift axis.
And, the HID joypad stuff works fine in UAE and MAME, that's good enough for me
