I agree, for me the beauty of the Amiga OS is that one can actually understand it. That the parts complement each other and build into something more.
In many ways is more Unix than Unix (;P) in that the "do one thing and do it well" philosophy goes far deeper in the actual implementation.
But to be realistic there are many warts and problems deeply ingrained into it too. There isn't IMHO much to salvage from it code wise, what is still worth a lot inspirationally is the integration and composability. That's the reason I liked the idea of a new generation "Amiga" based on QNX but that was not to be. :/
Actually even using the Windows NT kernel could give good results. The majority of ugliness of Windows is in the upper layers like the Win32/Win64 subsystems.