FWIW, I use both Opera and Firefox. Because I’m on dialup I keep Firefox up and running with gmail (Opera doesn’t support it very well, for some reason) and the calendar function, and also use it to download (frex) Youtube videos in the background while I surf.
I much prefer surfing with Opera, however. I don’t like using the mouse if I don’t have to, and Opera’s keyboard functions are far superior to Firefox’s. Ctrl + arrow selects links; A selects the next link; ctrl + shift + enter opens a link in a new window.
Of course, keyboard shortcuts aren’t everyone’s cuppa, and I’ve come to understand that I’m weird in that regard.
You have, just about single-handedly (or -postedly, if I may create a new word), persuaded me that I must try Opera. Maybe it’s because I used computers for so many years before Windows, but I lurve KB shortcuts.