Rated 5 out of 5 stars
Amazing time saver. I use both this and GMail Watcher, so I don't need to keep mail tabs open or check my browser every now and then. All I need is to keep a Firefox instance running and get both vocal & visual mail notifications.
I like that I can middle-click the button to check for mail immediately. I also like the "Reuse existing email tab first" option, that for some reason exist only on GMail Watcher but not in this extension.
One thing I dislike is that the extension doesn't save the mail counter when Firefox get closed, so when I restart Firefox I get all those flashy alerts for no reason.
Thank you sonthakit :)