The only two reasons to upgrade from Kickstart 1.2 to 1.3 are:

1. Rebootable recoverable ramdrive.device (RAD:). Of course, the actual recoverable ramdrive itself is new in this release.
2. Booting from A2090A Hard Disk.

And here are the changes in the Workbench software:

• New Programs
• Shell - a CLI with line editing and history features, I believe this was basically a new CON: device, called NEWCON: (which was changed back to CON: in Release 2).
• FixFonts - Updating the FONTS: directory.
• More - A text viewer, which often crashes my A1200.
• CMD - Redirection of serial/parallel to a file.
• Several new AmigaDOS commands.
• MergeMem - Merges different expansion board memory together to create a larger free block of memory.
• ClockPtr - Turns the pointer into a digital clock.
• InstallPrinter - Installs a printer driver.
• PrintFiles - Allows you to print multiple files.
• Updated Programs
• New printer graphics screen in Preferences.
• Several AmigaDOS commands expanded/revised.
• Devices/Handlers etc.
• The MOUNT command, and MountLists appear to be new.
• RAM-Handler (RAM:) now known as "RAM DISK".
• CLIPS: assign for clipboard.device.
• AUX-Handler (AUX:) for unbuffered serial.
• PIPE-Handler (PIPE:) for transferring data between programs.
• SPEAK-Handler (SPEAK:) for "reading" files.
• NEWCON:, mentioned earlier.
• FastFileSystem (FFS), a faster filesystem for hard disks (which could also be used with RAD:). This new filesystem had the side effect of enabling disks to hold 4.9% more data than before, although it is impossible to boot from.
• Other
• Demos removed.
• SPAT, DPAT and PCD AmigaDOS scripts.
• IEEE maths libraries.
• I'm not sure, but I think ENV: and SetEnv/GetEnv are new.
• More printer drivers.
• Startup-sequence now calls "StartUpII" (a sort of early version of "User-Startup").
• New CLI-Startup and SHELL-Startup scripts.