"Completely new user interface" is a straight-forward LIE. The only new things are the ability to move tab bar above the location bar and the new Firefox button which actually sucks big time and doesn't work like one could wish.

Haven't had a single crash, even after keeping FF running for 12+ hours and doing a fair amount of browsing, tab opening/closing etc.

Me neither and I actually use my browser all the damn time. Not a single crash or hitch. Though, maybe it has to do with the OS itself? I am running FF4 on Win7 64-bit and I got the impression OP was on Linux.

Fonts work fine on real OS's.

I needed a separate browser open with a different google login.

Just tried it, uses about 95MB showing google, compared to about 55 for Safari. Memory usage goes up form there Firefox memory usage grows quicker than Safari's.

I mean.. if your going to provide the option to modd up/down with reason, shouldn't those reasons be tabulated somewhere visible to the readers being modded? (Is it displayed somwhere and I've simply been missing it?)

Firefox+Firefox mobile is the best combo too, they integrate very well with each other and the mobile UI is great.

http://blog.jaybhai.com/the-tradition-continues-thanks-ie-team

Mozilla should've done the same for IE9's release.

It just is not normal for FF to idle on a Flex based application website and be using 88% CPU on my Mac. Chrome v10 on the same Flex site uses 31% CPU.

This is just a continuation of more of the same... aesthetics are not worth a thing if FF kills my CPU while idling.

Giant FAIL for FF 4.

Wouldn't be surprised if it's Pentadactyl

Tabs re-apeared this morning based on what got closed out yesterday.

They are just basically saying they DONT LIKE what you are writing. It has nothing to do with truth or facts. I'm sure most votes are emotional here. You say something negative (even if it is only facts) about their favorite software/hardware/company and you will be voted down.

#1 Statusbar gone.
Not just not enabled, gone.

#3 Tab misbehavior
I think Opera started it, but whatever the origin I see it now in Chrome, in Galeon, in Epiphany, and finally as the default in Firefox. Why in the world would I want the browser to try and guess at where to place tabs? A new tab goes on the far right, not somewhere in between my current tab and the far right.

#5 Forced search
Try this: Open slashdot.org in Firefox 4. Hit CTRL+T, then type slashdot.org and hit enter. Where did your new tab go? That's right, Firefox 4 guessed that you wanted to look at your *other* slashdot tab. This search-for-tab behavior could be useful, especially if you're me and have 200+ tabs all the time, but to do it by default and without recourse is rather horrible.

Chrome launches subprocesses for each tab and extension while Firefox uses a single process. With Chrome, you'll have 23 instances of chrome.exe for 23 tabs, and with Firefox, you'll have 1 instance of firefox.exe for 23 websites, which is the reason for the stuttering and slow down.

See link for animated counter of Firefox 4 downloads: http://glow.mozilla.org/

There is too much junk in the trunk. They keep speeding up the javascript engine but overall responsiveness is degraded.

Firefox 4 has already overtaken IE9 installed share.

"Firefox 4 has already overtaken IE9 installed share.

The whole point behind freeing up vertical space is so that you don't have to scroll.

Saying that a page length can be near infinite does nothing to resolve the issue for people running netbooks and who can't get a youtube video to fit in the available space.

Try "Tree Style Tab" extension.

NetCaptor 1998
Amiga's IBrowse 1999
Opera 2000

22px at the bottom of the screen rarely makes a difference in "have to scroll" vs "don't have to scroll."

Having a different browser UI for a netbook would be okay by me, but why cripple my desktop with 1280 pixels of vertical resolution?

Who said anything about crippling the statusbar? There was no need for Mozilla to gut the statusbar code in order to support transient status popups. Just because they did, that does not make an argument against transient status popups.

More so as screen resolution varies and more so again as defaults become ever more obese with OSes like Win 7. But, hey, don't let that get in the way of pixel creep: 'it's only 22px'

but I don't like how they're handling stuff like Adblock which I used to stick in the status bar. I'm glad the status bar is gone, but I liked using it as a dock for extensions.

Making a low-res UI optimization the default for high-res makes no sense.

there's a difference between yet-another-space-consuming-toolbar-of-questionable-utility and the status bar

which has been fundamental to browser UIs for so long

Two counts of special pleading and now an appeal to tradition. Dude, not cool.

The status bar in the browser provides useful information which I think is necessary, and, yes, useful for a majority of users.
...
Most users don't really care about URLs, either, but I still think the address bar is a necessary feature.

If this is special pleading then it is also such to suggest that a special UI be adopted for low-res