mostly speed. I had something work oriented to do that involved a lot of repetitive loads and clicks - it went by a lot faster when I did it in chrome. Also found a lot of the extensions I use in FF have been ported over. Not adblock, as far as I can see, but I'm so inured to ads anyway that it's a bit less of a priority for me.

I still use FF for development, but I think I'm good with Chrome for everyday LJ refreshing.