What does it do that OS4 doesn't?
Here are a few
pro arguments for MorphOS compared to OS4:
1. Cheaper hardware.
2. Faster hardware.
3. Better OS 3.x compatibility.
4. Better WarpOS, PowerUP and Warp3D compatibility.
5. Faster 68k JIT.
6. Better 3D drivers.
7. Better USB support.
8. Better foreign filesystem support (FAT, ext2, XFS, NTFS...)
8. Free OS upgrades (all MorphOS 2.x updates have been free)
9. Possibility to try-before-you-buy (burn the ISO to a CD, find a Mac mini somewehre, boot the CD and play around. It's 100% free, 30 minutes at a time. If you like it, you can easily locate Mac mini for yourself and buy the keyfile for it)
9. Good resale value of the HW (esp Mac mini)
10. Better OWB (web browser with flash, html5 etc) and MPlayer (very good video player).
11. Better desktop (Ambient vs. Workbench)