WARNING: POTENTIAL SPOILERS HEREIN!!!!
The two main characters are a bit stereotypical: Lynley is a bit too hard edged, especially considering how intelligent he is (in a recent PBS Mystery episode, "The Word of G-d", he asks a pivotal character how he should act when portraying a potential buyer of a stolen page from an ancient holy book; the character tells him that he needs to appear erudite and friendly, but brusque and no-nonsense, to which Lynley replies, quite tongue-in-cheek, "I can do that!"), while his partner, Havers, is a little too wimpy, considering her position (cops all over the world are given basic self-defense courses; in the same episode, Havers is knocked over while making a bad attempt at stopping a guy from running away).
However, the plots are well-constructed, and the pace is brisk to the point that you think you're on a roller coaster! I usually feel "cheated" at the seemingly predictable end, but I enjoyed it up to that point (at the end of the aforementioned episode, Lynley is taken away by four plain-clothes cops for abuse of power; utter nonsense! If anything, his tactics are textbook FBI/Scotland Yard!).
The only real problem I have with the show is that the characters speak too quickly (not even the closed captioning can keep up!), and, to my American ear, none too clearly!
Regardless, I enjoy the show!