My experience so far has only been with AROS. I moved recently and have not moved my aros box to my new house yet. I can tell you I miss it alot.
I'll move it back over here eventually, still settling in.
At my old place, Aros box was more of less my main computer. For what I do... Text editing, graphics and most importantly music making using milkytracker... I used fast tracker II and stuck with windows 98 till something like 2007 just because I wanted fast tracker... Under dosbox, fasttracker runs reasonably well, but I weened myself of it and use milky tracker now. One thing I like is milky, which is my main program runs on windows, linux AND aros... so I can work on any box.
Audio evolution for aros is in the works. I'm hoping I can get that and learn it and no longer need a windows box for adobe audition.
If aros gets audio evolution, a very good video editing program and
gets some major bugfixing/tweaking along with improved browsing I think it would be all I ever need.
I plan on trying out morphos once I get a 1.25ghz emac. I hear its alot more stable and useful on as everyday machine.
The browsing on all 3 platforms really needs to improve before people can stop dual booting to windows, linux or osx. There is also perhaps a bit too much emphasis on how all 3 run classic apps. I like classic apps, but we need brand new or ported apps much more than just good classic app integration.
Personally, I'm just glad there is still a road forward for all of us...
Steven