The title is "Pros and Cons using..." and nothing of daily use
OK and of course my comments are related to Aros 68k of course
If you would look at "daily use" then it is silly to compare anything amiga related with modern platforms like Windows and Mac (or Linux). Take only the huge software bases and development support.
By "polished" I thought of features, themes and icons are a matter of taste. I cannot say anything about that.
Aros 68k runs on both 68k real hardware (including Vampire) and UAE and amiga 68k software and aros can be mixed. Indeed it replaces the 3.1 components. On X86 it would run in UAE too. How much communication is possible between software environment in UAE and the host system is out of my knowledge. If running on 68k hardware or in UAE it is of course a normal 3.1 environment.
"So, you can't say it's a generic option on AROS, and even then you're forced to use MUI 3.8 or newer unofficial MUI branch which has the same issues as on OS4 too, so a "con" still."
That is more a con for MorphOS in my view. If there would have been interest MUI would have become a real standard on all platforms. Now there are lots of different and not compatible implementations.
"At least the hosted version I've been using has been constantly crashing with certain programs which came with the distribution, even with some built-in commands don't act as they should or crash. Maybe some other versions are better in this regard, but that's my impression."
I do not use hosted AROS myself so cannot say anything about it. On 68k it works very well.
"There are old Amiga users who pop up at Amiga IRC channels, who might have heard about OS4 or even AROS, but haven't heard about MorphOS."
Outsiders certainly... outsiders at highest have memories of A500 and similar. I doubt many know about the developments after Commodore went under. Then you should make more marketing for it ;). It is certainly a good OS, best PPC based amiganoid OS currently.
But still I doubt that many in current community are interested. Perhaps there is some potential outside but that is something I cannot judge.