I use Opera on Linux.
I’ve tried Opera before, but it just didn’t appeal to me.
I used to use Konqueror for everything, but now am using Firefox (actually Iceweasel) for most things.
There are things I dislike about Firefox...on x86-64, you can run the 32-bit-only Flash player, but there are weird problems sometimes. And, as the article states, it is a memory hog. It’s also pretty slow, even on a fairly powerful machine.