Great one, but can be even better! Rated 4 out of 5 stars
Your ideas about keyboard + mouse integration are great! ;]
However: some configuration options *in a dialog* would be more than useful. I would like to use the add-on just for text searching in tab titles/urls[which is great!]. Therefore I consider capturing ctrl+shift+tab as a big inconvenience! It forces me to use only your add-on and only its style of changing tabs, while maybe I'd like to use TreeTabs [or other] simultaneously, or maybe just stick to firefox's default tab changing way and use it for text search only.
Propositions of features:
* option to disable capturing ctrl+tab, ctrl+shift+tab
* option to customize keyboard shortcuts (covers the above)
* option to change thumbnail size
* option to remove / move the favicon from / in the thumbnail