[sjwright]

To add another data point, I'm using Firefox on the Mac with a half dozen plug-ins and I have never experienced pauses remotely like what you describe.

Furthermore, Firefox has been consistently smoother than my near-virgin install of Chrome. It's weird -- while Chrome definitely finishes loading pages a bit faster, it performs incomplete page repaints in the process, causing unpleasant whole-of-screen flashes as I jump from page to page. With Firefox, moving from page to page is butter smooth.