Having been on various sites that are 100% moderated, it's rare for it to work well unless there are a large number of active moderators, and even then, there's no guarantee. The trade off is usually that only one or two moderators really keep on top of things, who then place their own style preferences over any written guidelines, and in most cases, things wind up perpetually backlogged, and the site falls into an outdated mess.
DVD Spot (which is sadly gone) and Film Aficionado are the only sites where things have worked out OK, but on the same token, it seems like a lot of people are less inclined to contribute because the requirements for adding something are a bit laborious. Others, like RPGGeek, are an absolute mess - I've had some stuff pending waiting to be approved/denied for probably a year, and I eventually just gave up.
I think it's one of those "go that route only if you have to" sort of things, and personally, prefer the open, collaborative approach. Apart from the duplicates and occasional typo, we've got a pretty good community of submitters, and tend to police ourselves rather well, imo.
