I'm using Beta 4 on XP. It feels fast, and the memory usage has definitely been improved. I'm not sure how I feel about the new address bar, but I'm going to give it some time.

I've had one crash in 24 hours, and Google Reader didn't work for me until I created a new profile.

If you do have to create a new profile and set everything up again, be sure to exit so everything gets saved. I lost a few minutes of work in that crash.

So is FF3 ready yet? I can install it here on Gentoo, but I haven't yet because I wasn't sure how stable it was. Is anyone using it yet, and if so, what has your experience been like?

Their comparison of FF2 and IE7 don't match mine-- FF2 is taking up incredible amounts of memory over usage versus IE7 for me.

Probably the extensions, but, man, I'd love to know which ones.