People should note in particular a bloody brilliant performance by Sean Bean as a horrible, horrible Yorkshireman. Also the nastiest violent beating in police custody one might ever see. Also some poor swans.
Sam Wollaston, the Guardian TV reviewer expresses my thoughts quite well.
The mood is a dark and desperate one. This is a wonderful portrait of brutality and corruption, a huge and unstoppable machine from which there is no escape... It works beautifully, and maybe begins to answer a call for a new seriousness in television. Perhaps at last someone is sitting up and taking notice of what's going on across the Atlantic. And, like the best TV from America - The Sopranos, The Wire, Mad Men etc - it captures a time and a place.
I think a TV niche becomes significant to programmers not as proportion of population but as absolute size (for commercial broadcaster, as it relates to absolute ad revenue). I think the sophistication of British non-televisual culture shows that we have as great (or greater) a thirst for depth and complexity as the American population. But in absolute terms our numbers are smaller: 5% (say) of 65 million is much less than 5% of 250 million. Thus the pot of money appropriate to meet the needs of this audience rarely reaches the watershed which would translate into regular programming. Though there are two irregular programming slots - the BBC classic drama, and the ITV dark drama - which can aspire in this direction.
Where British TV does excel I think is in reaching a compromise between reach and depth - because a proportion of writers, producers and directors are aspirational in this way, clearly read and view the books and films and shows that achieve depth - there is a large pool of talent who work to bring depth into popular shows. This is absolutely not to be sneezed at, and I'm not belittling it at all. There are many British dramas and comedies that I love.
However, I think that like books (let us say, SF books) there needs to be a pool of highly sophisticated non-populist - or even avant-garde - product for the writers of popular product to draw on. Only a tiny proportion of people will buy or read this product, but it improves the quality of popular product by indirect influence.
I think we have been lucky that there is an external source of this product in TV - in the relatively small, but in absolute terms large - American market for quality TV. Of course the pan-European demand is bound to be even greater, in absolute terms, but fragmented by language.