I have always hated Opera, especially since they want you to pay for it.
A few reasons Opera is superior to firefox:
Faster
Nope. Perhaps your Firefox is set for dial up?
Mouse Gestures
I hate mouse gestures. But you can use them in Firefox I believe, as a friend of mine who also has a huge hard-on for mouse gestures stayed with Opera because of that, but now he uses Firefox exclusively.
better downloads interface
I don' t understand this. Firefox just shows you a bar as the download progresses. Does the download bar in Opera look fancier and sparkle or something? I fail to see how right clicking and downloading could get any " better" .
Bit Torrent client
I hate bit torrent. Slowest form of download possible it seems, and you' re dependent on everyone else already having and seeding the file. If they don' t, you' re screwed.
IRC client
I hate chat rooms. They are teh ghey and only teenagers use them.
better tabbing
Firefox does this pretty well, the only thing that could be improves is the amount of dead clickable area when I try to close a tab... you have to click on the tiny " X" in order to do it.
voice
The browser reads any/all onscreen text for you? I believe the Mac OS does this natively. At least I know OS 7-9 did it, and it wasn' t limited to web browsers.
widgets
Mac OS has built in widgets if you really have a fetish for that kind of thing.
real full screen
As opposed to having the BACK and STOP buttons at the top? I never let my browser take up the full screen anyway because my screen is just too awesomely huge.
looks better
How so? There' s nothing to look at if you have " real" full screen.
better security record
That' s because very few people use Opera in comparison, so the 1337 kiddies don' t try to haxxor it.