Man I thought Opera was fast until I used Chrome. And if you read the comic they put out, or you're interesting in programming at all, you can appreciate it even more. Every tab and plugin is a separate process in the OS, so individual tabs can crash, or even individual plugins like Flash and have no effect on th rest of the browser. Every tab is completely sandboxed which allows for some security benefits. It's fully multithreaded as well - no more hanging processes because javascript never returned control to the browser. And when you close a tab you kill a whole process, so all the memory is relinquished, unlike Firefox's fragmentation issues where closing a tab doesn't necessarily free the memory it was using.

Bye Firefox... you bloated, slow, crash prone garbage