I help run http://www.armorama.com and think it is a good overall site. We do not get a lot of reviews though, mainly because we do not have a corporate sponsor to help acquire the kits for review. Users are welcome to conduct reviews on their own and submit them to the site for publication.
Perth Military Modeling Site is another great place for reviews. Their proximity to the manufacturers in the Far East means they get the latest releases from there first.
http://www.perthmilitarymodelling.com/