I thought the characters were more quirky and nuanced than characters in modern middle-of-the-road dramas like East Enders and The Bill. They didn't converse at shouting-level the whole time, for a start, and they seemed a bit less bog standard. They did things like doodle in their notebooks, and forget what they were saying halfway through a sentence. All the incidental characters had little back-stories.
While I was thinking this I also reminded myself that along with this quirky individuality, TV was more conformist. Everyone living in straightforward nuclear families and so on. But just as I thought this - bless my soul - there was a gay character. And he wasn't presented as a figure of fun either. He was arrested by 'Fancy' for speeding. We saw him talking on the phone saying 'the policeman who arrested me was like a side of beef'. And then at the end of the episode he asked Brian Blessed to go out for a drink with him. Alas he was refused, but I thought it was a nice touch.
All in all I thought it put modern mainstream telly to shame.