I've got the complete opposite impression.
from the outset it looks like a bad rip off of Chrome.
i'm finding it hugely unstable (keeps not responding when new tabs are opened) (I'm browsing with three windows open 3 tabs in each, was using far more windows and tabs in each window yesterday in v3 with no problems).
I'm finding it can't open PDFs, trying to open a PDF will make the browser lock up (every tab/window goes not responding), and when it comes back to life i've got a blank window rather than a PDF file (viewer is adobe reader X).
all in all, I'm pretty much wishing I'd never upgraded,
and am posting from Chrome because it is at least stable. whilst firefox on my machine is not.