Just went and pulled the trigger yesterday. On my Macbook, I flipped my default web browser to Google’s Chrome.
I had been using Apple’s Safari. The main reason that Safari won out over Firefox at the time was that Safari actually supports Apple scripting (of course). I don’t really take advantage of that any more though.
Even with Flash turned on, Chrome just feels faster and cleaner. Nothing real definitive or quantitative that I can point to though. Basically a pure gut feeling. Your Mileage May Vary.