Hi,
see
http://www.gregdonner.org/os39faq/whatsnew.htmland check it out yourself.
This FAQ lists all the fixes etc over 3/3.1
You may find it's suitable for you, I did.
I run 3.9 on a A1200/BlizzardmkII/SCSI system with 32 Meg fast RAM and its nice.
Regards, Michael
aka rockape