I find it quite funny that people have started to find every slightest flaw of Firefox since it has gained a significant share of the browser market.
I love the rhetoric used in the article's title to make it seem Mozilla admitted Firefox was a flawed browser. Goebbels would be proud.
Opera is a nice browser, but her sister's hotter. Isn't bloated with features I could care less about , extensions give me a way to customize my browsing experience (and there is an almost incalculable number available), and it's open-source. Actually I could care less about the latter...
The memory footprint argument is always mentioned. Yet my Firefox at this very moment uses 180mb. But I live in the 21st century, I don't have 1GB of ram for nothing. It's still bloody fast, and I won't switch for a 2 milliseconds lesser loading time.
Secure ? It is most probable that if Opera had the same number of antagonistic fanboys it would be as flawed in the end.