Regarding AROS, it's been awhile since I've played with it. I did try MorphOs, and it's very nice, and running classic software was very seamless and fantastic...BUT running on old hardware doesn't really appeal to me because it seems like a dead end, much like the Amiga was hardware wise (towards the end of days).
I've always like where AROS was going, but it was just not "there" yet.
Is it stable enough these days to be fully installed on the HD and run as a daily use desktop machine? I would like to write some code again for the Amiga... just as a hobby, but I am hesitant to dual boot it if there is a chance it's going to destroy my partition table and wipe out osx, windows, etc.
I realize it's not as finished as MorphOs, but it is open source and it runs on modern hardware so I think it has a better longterm outlook.