Most of the devs I know use one browser for everything and IE for testing. I take it you use FF for dev because of Firebug and Web Developer Toolbar and Chrome for browsing and personal stuff?

No, the opposite.

Out of curiosity, why's that? Why do you need a browser for dev and a different one for actually browsing the web?

I like the Chrome Developer Tools, but prefer Firefox's customizability for my personal use. I can install things like Vimperator/Pterodactl for Vim-like surfing, things like Ghostery to block monitoring sites, etc. Also, the high level of customization in my Firefox profile makes it unsuitable for testing sites.

Well true, Chrome was always the best for browsing, and Firefox for developing, but now that Chrome's web tools kicks Firefoxes ass, you can use Chrome for both :) Or just separate it, Canary for development, and stable/beta/dev for browsing :)