[dmunoz]

I don't know how well it works on a OS X, but I have been using the firefox-ux nightly build on Windows for awhile now. You can find them at [0]. It's been as stable for me as the other nightly builds tend to be, which is very stable, but do be aware that going this route can lead to running into bugs. I understand why these things take a long time to shake out, but it is massively disappointing to hear that the new UI won't be released until Firefox 28 or later!

[0] https://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/late...

[abrowne]

I've been using UX Nightly on OS X as my primary personal browser for something like 6 months now and it has given me very little trouble.

It's worked well on Linux, too, but I haven't used it there as much.