Well, each of the 3 systems is different and have their own merits. Only OS4 and MorphOS can run 68k amiga software; AROS requires them to either be run in UAE or be recompiled. OTOH, AROS runs on available hardware...
If you get a PowerPC card, you can have OS3.x, MorphOS and OS4 all installed and switch between them.
In my purely subjective opinion,i prefer OS4 to MorphOS and OS3.x, but at the end of the day, its all good.
