I'm using AmigaOS 3.9 on my main A1200, AmigaOS 3.1 on my second A1200 and AmigaOS 2.1 on my A600. I do also have a A500 in storage on which I used a highly modified WB2.04 floppy in the past.
I kind of like the idea of using all versions of AmigaOS that I have used in the past.
