Excellent! Finally found a tab rename extension that allows renaming based on only the original tab title instead of just the URL. Great if you you have multiple URLs for the same tab title that you want to rename. Survives session restarts as it stores rules and applies them when the page is loaded.
Only one suggestion is to add "Smart" to the actual extension name in Firefox (now named "Tab Re(gex)namer")

Very useful for long tab titles with little info