I thought what you're saying are Linkscanners like virus site scanner, but I was wrong. ...coz I was thinking of Virus Total. So I voted for WOT but also has Webutation installed, coz sometimes WOT didn't give ranking or taste of some sites I visit.
I have never encountered any browsing protection extension I do actually like. So I do use: For Internet Explorer 9 the SmartScreen-filter, which is really powerful in my eyes (with some unintended help of the Tracking Protection). For my main browser Google Chrome (beta channel) I like to use as least extensions as possible, so the only one I have installed is Adblock Plus. It is a shame Chrome's malware and phishing protection is not as powerful as the SmartScreen filter of Microsoft, however Chrome's sandboxing (with --safe-plugins) makes up for that. (The ideal safe browser, in my eyes, would be Google Chrome with Microsoft's SmartScreen-filter and Microsoft's Tracking Protection solution [so I don't have to install any extension].)
LinkExtend - highly configurable (I would set it on-demand, if I used it) and uses multiple services.
I'm not yet using any type of "Linkscanner" but I soon like to test the BitDefender TrafficLight or G Data CloudSecurity.
I have AVG 2011 which includes a Link scanner. As far as I can see, it is an "infection" orientated device and therefore has a security/technical basis acceptable to serious computer users. WOT, which I do have is a moralistic public opinion facility which does not concentrate of infection risks entirely but takes into account members opinions on matters not related to infection, but centres on the dubious subject of moral attitudes. Opinions ? Everybody has one.
I think there is this attitude with WOT, but it works well as an extension on every browser I have tried it with. I feel a bit naked without it to be honest. Some of the guys on the K-Meleon forums have suggested it's a bit for old ladies! Most of them are running Linux distros with KM on WINE though I think. It's easy to mock when you are running a Nix OS. Those of us running Windows have to be more careful.
Should've voted LinkExtend or TrafficLight, WOT is becoming too biased and inaccurate by itself for me.
None. Seems like a silly idea if it's user-reported, too untrustworthy. It also doesn't account for when sites have been hijacked.
I assume this has a performance hit? I couldn't justify using one. I've already got an over-the-top system and I'm probably going to uninstall MSE/ Comodo and just use the Comodo HIPS