Thanks for clarification on what WebRep does. Based upon what you just wrote and my experience with WOT they do different things. People may be critical of WOT but I have found that when they warn in red on a URL it can be because of malicous software. I have checked a number of the websites that they warn in red about and have found them to contain malicious software. I think that they also warn for content but this generates a ton of false positives because a number of webpages that have been identified by WOT in red are not PC websites. No need to expand on this.
Well, I'm certainly not saying that sites of suspicious content cannot simultaneously host and push malware - I suppose it's quite likely. But since avast! has Web Shield and Network Shield - which should block access to these sites anyway - WebRep isn't meant to deal with that, but rather focus on the content. (I know there's been a discussion here on whether WebRep should show the infected sites in red or not... I would rather vote for not, or at least have a special symbol/color for that, but I understand that's a questionable point.)
Of course, since WebRep is based on user submissions, the results will never be extremely reliable - but I'd say the users are certainly better in judging the content than performing a malware analysis of the page.