I never really got the whole "expanded uber-Amiga" thing?
It works well enough for me. It's a nice compliment sitting side-by-side with Windows.
Just seeing Windows by itself, Windows seems sufficient, but with an uber-Amiga next to it, the functionality Windows lacks is pretty well magnified and offset by the uber-Amiga.
It's also trivial to fall back to a more compatible mode for the old stuff.