Since these are older plugins (often associated with the "hot" design trends of the early 2000s vector art scene), the most useful modern feature would be one that automates the tedious process of creating complex, organic variations—something that is still time-consuming to do manually in Illustrator today.
This review covers CValley FILTERiT 5 Xtream Path 2 , two veteran third-party plug-in suites for Adobe Illustrator cvalley filterit 504 and xtream path 204 win mac hot