I prefer Firefox because I can add the functionality I want and theme it to my heart's content. Opera is limited in that respect, so like with a hard shoe it breaks you in, not the other way around. I rarely find the need to use another browser, except for Windows Updates and other IE-only sites, in which case IE7 gets the job done. However, Opera does see some use as my third-string browser.
The deciding factor for you would likely be the third-party software. SpywareBlaster and Yahoo Toolbar only work with Internet Explorer and Firefox, so their presence will not be felt if you choose Opera as your #1.
For comparison sake, Cnet has not done an official side-by-side but you can click here for the Opera 9 review, in which Robert Vamosi does make comparisons between the three top browsers and hints at why they ran Firefox ahead of Opera.
Hope this helps,
John
I am looking to switch out of this old and tired IE scene. I have been reading up on FireFox and Opera and I have to say I am having a very difficult time deciding between the two. I am also concerned about some software that I have not being able to integrate into either one (TuneUp Utilities 2006, Yahoo Antispy, Spybot S&D using the tea timer and Spyware Blaster.) Everything I have read about Opera and Firefox has been good and I would like to see CNET do a side by side test with Opera and Firefox as they did IE and Firefox. Can anyone help me decide or tell me if there already is a side by side of the two?

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