The standpoint

This is from the standpoint of someone who does software development, frequently in a web context. I switch between them - I like FB for the leaner interface, but Mozilla for development.

You can't beat Mozilla for web development. The httpliveheaders extension makes it easy to see what's actually going on, cookie control is wonderful, the DOM inspector and Venkman (for JS) are both great.

Contrast this with troubleshooting things in IE, where I habitually run a proxy in debug mode in front of it just to see what's happening on the wire.

I know a lot of folks care more about mob-standards than actual standards, but Gecko is very, very good, standards wise, and is much easier to write to. Given that we've had two large projects recently where we didn't have to worry about supporting IE's bugs and missing standards support, that was a huge win (when we do have to support it, IE support is usually about 10% of the total project cost.). We've changed how we quote projects based on that fact, as there's an emerging group of companies that don't need IE for intranets.

Tabs are something one either loves or hates. Personally, I love them - hit the third mouse button, a reference loads in the background while I keep reading. It is right there to reference when I want it. Semi-nonlinear reading is massively improved by this - rather than interrupting the flow by either moving away, or popping up a new window, references become a simple thing to move to when it is appropriate. If you don't like it, fine; I find I can't live without it now. (I've seen the XP style make-appication-buttons-a-menu trick, and I'm honestly not impressed. As UI for browsers, it is near useless, because the text in the titlebar is insufficient for distinguishing between different pages on the same site, on most sites. Plus, you have to leave your current window, hit a button at almost, but not quite at the bottom, and select from that. If smacking the cursor to the bottom of the screen got you to the button, that would almost be OK, but you have to aim slightly above the screen bottom. I haven't used XP for a while, but I think there's even a delay before the menu appears. Not a natural series of gestures at all, and very different than the haptic of using tabbed browsing.)

Add in control over whether ads display, flash runs, popups appear, who gets cookies, overriding annoying things frequently featured on Geocities sites, and I'm left wondering why anyone runs IE as a primary browser.

I know I'm an anomoly - I do software, I run Linux as my desktop, etc. But damn, every time I use IE for normal browsing, I'm amazed at how broken and annoying the web is.

Just my two cents.