From my perspective AmigaOS4.x doesn't bring nothing new to my "Amiga" experience (sure, it is nice, there are few other things, I will share my experience later). ALL software I want/can use was written for AmigaOS3.x and actually it works even WORST under AmigaOS4.1 (glitches etc.). Sure, there is few games, "new" calendar... etc. There is no any software that "needs" AmigaOS4.x. Only difference between OS3.x and OS4.x is NEW hardware (expensive and "if" available), so system is faster, but from productivity point of view not much changed in last 10 years of OS4.x.
I have no idea why PPC was selected as a future CPU for AmigaOS, AmigaOS4.x is NOT "compatible" with any AmigaOS3.x software (as far as I can tell)! What would be a problem to "emulate" compatibility in the same way as today on AmigaOS4.x but do this on intel CPUs?
Sure, someone invested 10+ years of work/money into AmigaOS4.x, but it looks for me as a DEAD end, in next 10 years PPC will be obsolete and AmigaHW WILL be dead with it.
Considering that AmigaOS is super niche system, we should have HW platform that is CHEAP and AVAILABLE. AmigaOS should be like a virus that can be installed on the most common "host" to create base of users that will be attached to SYSTEM, no hardware.
Ask how many MacOS users cares about intel CPU vs. PPC vs. Motorola, not many. During AmiWest I heard that best Amiga to UAE Amiga...