Things FKiSS/Unix does better:

Supports "add-on" sets by specifying multiple LZH filenames
Provides an easy way to view comments, etc.
Recursive open of LZH files (archive-in-an-archive)

More "Features" from other viewers:

Ignore excess characters in FKiSS action and event names
Invert sense of ghost("cell")

In no particular order...

Better UI feedback on which page/set is currently being displayed
Add "Clear" button to error log window, add View Errors menu item
Automagically scroll to first error in current set in Errors
Implement "maximum fixed" property of cells
Remove arbitrary limits
Improve interactive response during FKiSS / catch endless loops
Handle sound("") and music("") as other viewers do
Build a real parser so that all syntax errors can be spotted reliably
Do LZH natively, and generally support it better
Editing features :)
