Last time I used it. Long time ago.
I rarely use anything but Opera, now.
Firefox is just too girly. Every time there's an update, you have to wait ages for updated versions of extensions and, without the extensions I use, Firefox is almost unusable, for me.
Opera has those things (Tabs at the bottom/Paste and go/etc.) as standard.
Well, that's Google. I trust them about as much as I'd trust my cats to look after a canary.