I may be the odd man out, but I like the new Firefox ...
+1. I found the old interface clunky and awkward. I think this change makes Firefox a real contender. And it may only be my impression, but the new release seems a lot snappier, at least in Linux.
I still use Chrome (Windows) or Chromium (Linux) the most, but it's tiresome to have to turn off all the "Peeping Tom" features every time they push an upgrade.