sure Fran.. but who's going to want to boot up a 512k A500 to run Dpaint with very little ram left? Or to do the same and run the boing ball and clock w/a CLI showing the 'dir' command output.. lol.
Take for example a expanded amiga and try see which OS lets you send your email quickest! AmigaOS will for sure win on such tasks, so i would call that a advantage. Linux and Windows is slow and not very responsive even if you compare a modern pc with lets say a slow AmigaONE running OS4.
It is no secret that it lacks quite a few modern features thanks to the developement being pretty much stalled since commodores demise. It does still however have some areas where it is better, which includes the fact that it is very lightweight and responsive compared to even the most lighweight linux distro running a lightweight window manager.
In the end it all depends on what YOU use your computer for.
I see no reason in switching to windows, linux or even mac if the amiga has to software to do your tasks just fine if not even better than your powerful beige box. If abiword has enough features for you, then why switch to a pc running word or openoffice? It would be no point, as it would actually take you longer to do your task then.
Same thing with computer upgrades.. Alot of people upgrade or buy a new computer, even though all they use their computer for is web surfing, email and some simple text editing. What is the point of using a new core 2 due with latest GFX card if your only using these apps? When your older PIII would do the job just fine..