Lightweight & works perfectly Rated 5 out of 5 stars
I've wished for an extension like this for a long time -- it's going to be invaluable on forums that only allow for a really short signature, as I change my sigs on a regular basis. Happily, it isn't increasing Firefox 21's CPU or RAM usage, even though my computer's fairly old (2GHz Centrino running Mepis Linux).
The only things that I think might improve it would be things like:
-- at least some control over where the statistics appear
-- have the info collapse after an adjustable period of time has passed with nothing highlighted, possibly then available in a tooltip if we hover over the icon
-- choose between having the info automatically visible or appear only as a tooltip for the icon (I'd go with icon)
In any event, I hope this extension remains active for a long time!