Part of a feeling of being incomplete in my opinion is due to the fact that almost daily theres new work available, not always heavily tested, or complete.
OS4 and MOS both differ in that what people end up with is akin to a light distro, and one that is worked on by core developers, meaning that releases content is more heavily controlled, and aimed towards a much more restricted hardware base.
Find or buy hardware that is properly supported, and use a distro rather than a nightly and AROS behaves equally well.