Yes, I'm quite sure. On OS X, I can get real full screen with Chrome, and I can get it with Firefox if the website itself initiates it. But the "full screen" in the View menu removes half of the chrome and leaves the other half. Useless.

It turns out I'm not the only one complaining. It has been a known issue since at least early 2012. Apparently, some of us think full screen should mean FULL screen. Nobody at Mozilla is working on it: https://bugzilla.mozilla.org/show_bug.cgi?id=740148