If you really need 100% compatibility with AGA and
other hardware centric things, I suggest you
keep using the classic Amiga systems. MorphOS and
OS4 are targetted at people interested in a
modern re-implementation of the AmigaOS and the
more serious apps/games released in recent times.
Removing the dependency and compatibility of the
classic hardware is one of the goals of these new
OSes so I wouldn't keep your hopes up for AGA or
other hardware emulation, other than UAE.
You should try to understand more before posting
such "out of context" generalizations about both
platforms though. Oh and "9 fingers" isn't AGA
and it doesn't use AmigaOS either
(direct hardware banging like most older demos)...