In spite of potential unreality and exaggeration (I am not sure that a person like that could be in contact with young people and assist authorities nowadays), but the concept and its realisation are really distinct. True, the cases are not equally interesting, but when the wrongdoer could be guessed in advance, there is always a twist in his-her motive and some aspect the viewer (as well as the police) was unable to ascertain...
The gem of this Series is undoubtedly Koen de Bouw - he is really something, so different from his other performances; I have also briefly looked at remake trailers and must state that no other actor in the role of Professor T. Is up to this task. Plus, here my another favourite was Goele Derick as Ingrid Sneyers. Well, the remaining cast was good as well, though I was not fond of certain replacements in Seasons 2 and 3... As for the latter, I disagree with those claiming that Season 3 is worse or unnecessary, I find it pleasant change of venues and skilful roundup of the story, no hasty finish due to less viewers, lack of funds, etc.
Thus - 10 points for performances and depiction of "crazy moments", 8 for the smoothness - 9 in total. Good work!