If you have an RTG system with a big hard drive ie > 4 gig then OS 3.9 is nicer and less hassle. Its also nice to get a free TCP stack for internet use. But then you have to put up with a reboot on cold start. I did have an A4000 with a CV64 and newicons with tool manager and tools daemon, magic menu, simplefind, arc extract, Miami and DOpus4 and a 4 gig hard drive (only 50% full at the time). This was functionally the same as OS 3.9. But I got OS 3.9 anyway and I still HATE the cold double reboot. And there are few useful utilities that only work with OS 3.1.
If you have an A1200 or less with no rtg and hard drive less than 4 gig, then stick to OS3.1 with Magic workbench, 8 colors screens, magic menu, tool manager, tools daemon, MUI, simplefind, Arc extract and Diropus4. The icon system in Os3.9 is slower and looks ugly in less than 32 colors, especially if you only have PAl or NTSC screens. If you have an accelerator, this OS 3.1 system will fly.
