Far too inflexible to be broadly useful: it filters based only on fully qualified URLs and has no support for Regular Expressions or wildcards of any sort. This means that it can only match per specific page, not per domain nor even sub-domain.

Example of what won't work: If a site uses text in its site-wide page titleing that causes problems, you cannot filter out the offending text for the title of every page on a site with just one rule; you would be forced to visit every page of the site and create separate rules for each one. If you like to save copies of Web page, as I do, and a site for instance uses the Unicode character "→" in place of a dash in page titles, you would want a single filter for the entire site - perhaps even the entire Web - to match that Unicode character and replace it with a "-" dash.

Nope, can't do that with this extension. The only way to accomplish that still is to use a filtering HTTP proxy like privoxy or Proxomitron, and those are mighty broad brushes for just filtering page titles and nothing else.

Addendum: Fast forward eight months from my review, and its developer has listened and agreed and added regular expression parsing. Unfortunately... that parsing is applied to the URL to be matched and not the title, which is necessary to solve the scenario that I described. The title of any matched URL can only be replaced in its entirety, not altered partially by regular expression.