Excel arrays are difficult to work with, exceedingly slow, and didn't have some basic formula support.

This looks like a very sane implementation, addresses some issues with traditional arrays (while extending them nicely) and implements those much-needed formulas.

You could call a named range or ctrl+shift+enter to run an array command. You couldn't put a defined array in a single cell, it would read at text.

These arrays are IN A SINGLE CELL