I'm not sure if I can post a link (or name) other sites but I came across a strange 'confrontation' between one of those system reviewers and a fairly well known purveyor of such a system.
The reviewer is Iain Lewington (bettingsystemreviews.co.uk) and he's evaluating the 5 Star Tipster system.
Would also be interested if anyone else has experience of either of these guys.