I've been using Firefox for a long time, and liked it a lot. Recently that long honey moon period started to wane. Firefox 2.x has some pretty annoying performance and memory management issues, regularly chewing up 700-800Mb of memory (on a 1Gb machine), and hitting 90-100% CPU resource. Admittedly I have 4-5 windows open, with 10-20 tabs in each, and a bunch of extensions installed, so I run it hard, but none the less, the problems are there. I was also sick of fan-boys explaining away issues (even refusing to admit there were problems), with comments like "it's the extensions, duuude", or "what do you expect with so many windows, duuude". Neither of these are reasons for chewing up all resources on a machine. Opera was starting to look mighty shiny.