I absolutely *LOVED* it. Finally managed to see the rest of the series and am so glad I stuck with it, I liked it from start to finish and the last few episodes were even better than the first half. I did think it was very British, I have to say, and I normally don't like British TV shows at all, but this was the right mix of humour, mundane quirkyness with a bit of suspense thrown in. The last episode clearly suggests what will be taken up in the next series, I think.
I haven't seen the pilot, only a few clips on youtube and I am so glad they replaced some of the lead characters, they seemed rubbish from what I could make out in a few minutes. ... and the accents, ewww, toe-curlingly annoying, and I live in the North of England.
Now, just need to master the art of patience.