Rated 1 out of 5 stars

needs better documentation - seems broken

the editor is very difficult to use - it inserts many spaces/indents at random when inserting a line break

i wrongly assumed you could set and save headers on a per-site basis like Mason - nope

no toolbar button

This review is for a previous version of the add-on (0.3.5). 

Hi man,
the regexp feature was planned and will be available since version 0.3.6 (currently in sandbox). The documentation you can get is at the first page of http://code.google.com/p/headertool . Where is also available the new "@regexp" syntax.