I use NoScript and loading the page with scripts disabled (the default setting for NoScript) I don't see any problem. But based on your report, I don't think I'll allow the scripts to run just yet.

Are you hanging on Google's redirect page or on the site itself?

Is it an indefinite freeze, or do you eventually get a dialog allowing you to stop/continue a slow script?

Does Firefox ever display the Mozilla Crash Reporter dialog? When Firefox crashes, it usually records information about what was happening at that moment. You can submit that data to Mozilla and share it with forum volunteers to see whether it points to the solution. Please check the support article "Firefox Crashes" (especially the last section) for steps to get those crash IDs, and then post some of the recent ones here.

I get the usual pop-up dialog asking to stop on continue the script.

It is not hanging indefinitely as I'm still able to open the Web Console (Firefox/Tools > Web Developer) and close the tab (this can take a few seconds though).

The browser basically becomes unresponsive. It does not matter if you go through the link with google or directly. I never saw the popup box. It's also not working in chrome, but I don't lose the entire browser and all the tabs, just that one tab which I can close.

You may have installed an extension (Web Developer and Firebug might catch such an event) that is preventing this alert from showing in time assuming that you never have increased this timeout (dom.max_script_run_time and dom.max_chrome_script_run_time have the default value).