As long as Firefox is the only browser where complete versions of add-ons such as NoScript, RequestPolicy and many others are offered, it is with no doubt the safest for me.
Which parts of noscript do you want? If you want to block javascript fully on certain sites, Chrome can do that without an extension. If you want to block external scripts from certain URLs, that should be possible soon through the webrequest API. I can't see any equivalent of the clickjacking protection, though.
I want whitelisting with a little dropdown that gives me the option to temporarily or permanently whitelist domains as I see fit. I'm not really interested in blacklisting, which is I think what you're describing.
I've been following (and looked back at) NoScript's development and realized that it does much, much more than blocking execution of scripts and clickjacking protection. XSS-protection, their ABE-system and the ability to block all kinds of media content that I want, are among a few. Much of it appears to be hidden "behind the scenes".
But mentionning that wouldn't fit in the marketing speech of Google and Microsoft (which pulled _exactly_ the same stunt a couple of month ago, IE slightly on top of course)
Microsoft has actually released numerous studies through NSS Labs. However, I believe what you are explicitly referring to is the yourbrowsermatters.org campaign. That was not a study, it was a marketing site that mapped the browser's user-agent to a listing based mostly on past NSS Labs studies.
As for the study from Accuvant, I definitely encourage you to dig into as deeply as you feel appropriate. Unlike the pro Microsoft reports from NSS Labs, this Accuvant study is completely transparent and verifiable. The methodology is documented and all tools and data sets are provided. If you have a legitimate concern with its merit, then you should have all the information you need to address it.
