Not that it matters, this thread could go on for a thousand years and someone will get 10 gazillion different answers along da way.
Am a FF kinda person. ( or one of it's relatives) It's the wordpress of web browsers, anything someone could want ... There's probably an addon/plugin for it. Plus like the transparency of it. Someone wants to dig into it, they can really get under the hood and tweak to their hearts content. Keyboard shortcuts ? Abound in pretty much every browser known to humanity. lol ... when in doubt, Google is always there. Also recall noticing FF+kin are more resource friendly than some others. Which is important to me ... grates on my nerves when any software becomes a resource hog without earning its keep. If x browser is going to use up more of my CPU or RAM. I better get a noticeable benefit outta the deal.
Being a compulsive software tweaker, spent more than a tad bit of time over the years learning to tweak FF/etc. With XP, have the latest stable for chrome/opera ... and FF on it. That FF 7.01 is as fast or faster than any of the others. At least, far as I'm able to tell anyway. Maybe .00001 secs diff ... maybe. Though I tend to disable prefetching, don't like it. Or could use some stoopid rendering tweaks that make it look like it's loading faster. But overall increases the time a webpage takes .. etc. And actually for me, FF ( and family ) seldom if ever hang vs some of the others which I think do more often.
iceweasel more or less IS firefox. Just the unbranded Debian version of it. Am typing this on iceweasel 7.01 now. Works well enough for me, shrugs. Think saw summin on LM homepage about them being in talks w Opera. Which I have no thoughts on one way or the other. Whatever LM wants to do is ok by me or whichever people prefer ... For me its likely going to stay something mozilla or related for the foreseeable though. Find it funny what people state as their reason to prefer one over another a lot of times. Screen realestate ?
Takes me all of 2 mins to customize a FF based browser to have as much or more viewport as any of the others. OR hit F11 ( aka: full screen mode ) if 10 pixels is that big a deal, lol. Whatever someone prefers ... *thumbs up folks. Besides this is gnu/nix. Who says anybody can only have 1 anyway ? There's my ode to da blessed FF and pro-mozilla rant.