Rated 5 out of 5 stars

Most useful add-on. And not only for the very convenient search operators it provides, but also because it can be placed in the menu bar and it allows one to hide TB normal filter, thus saving a great amount of precious vertical space.

I'd have one request: whether the appearance of the quick-filter buttons could be optional, so that people, like I, who don't use them could save some horizontal space in the menu bar.

Thank you for this awesome addon!

This review is for a previous version of the add-on (0.8.8). 

Please try 0.9beta @ https://github.com/wangvisual/expression-search/blob/master/beta/gmailui-0.9-tb.xpi