I'm using it at my work machine (because I'm eventually going to re-install from scratch anyway, and I don't really care what happens to it). Seems to work fine, just as good as 1.07, if not better. Still has a few glitches, but nothing too noticable (tells me it crashed if I close it with open tabs, even though it didn't, I closed it... might be an XP thing). Some extensions work for me as long as I update them. It's free, give it a try.
I have a friend using the G5 optimised version of 1.07 though on his iMac, and it's really nice. If you have a G4 or G5, I'd stick with that for now. Unless you can find a Gx optimised 1.5.