I somehow missed the first two series but after this one I am a fan. I am a self confessed nit picker in TV and film dramas, to my wife's annoyance and the ONLY thing I would question in the final episode was the shot (2?) from the bridge into the RR.
It looked like a couple hundred yards from a 9MM short barrelled weapon. It was not an MP5, MP7 or something else? Anyway I will get the first 2 series on DVD. Good show and believable, not a fantasy like some others.
Definitely some of the best telly I've seen in a long time. I am also a latecomer to the series but recently signed up at the BBC Store (http://store.bbc.com) and a day later I received an email from them with a 50% off code. So I've just bought the collection of both series 1 and 2 for £8.99!