I switched to Firefox a month ago, and so far I've seen:
-No popups
-A huge decrease in the time it takes to load pages
-And tons of useful extensions.
Admittedly, I'm not an expert on security concerns, and I haven't really used Mozilla or Opera for more than an hour, so I can't objectively say Firefox is the best. But I can say that I have no complaints about the browser as it is, and love many of its extensions.
-No popups
-A huge decrease in the time it takes to load pages
-And tons of useful extensions.
Admittedly, I'm not an expert on security concerns, and I haven't really used Mozilla or Opera for more than an hour, so I can't objectively say Firefox is the best. But I can say that I have no complaints about the browser as it is, and love many of its extensions.