I spent a dozen years working with the Pick system, both programming and helping produce the publications listed at
https://sites.google.com/site/masteraddressfile/misc/ppp and even making a number of the original edits to the referenced wiki page.
In a 1985 critique of a rather poorly written book about the Pick OS I mentioned that some of Pick's most obvious characteristics were a good spooler but a lousy editor, that ordered files could only be traversed in one direction and only after a sort, and that there was no application-style input processor.
The system had many great features, but also many flaws and omissions. The biggest problem is stated in the wiki: Pick Systems was too focused and licensing and litigation, and devoted relatively little effort to marketing and improving its software.
