DCI Banks has been a pretty pedestrian but serviceable police procedural. I mainly watch it for Stephen Tomkinson and the guest stars. But something odd happens in this, the fifth series. It got better! I haven't checked, but my guess is that they ran out of the novels on which the series is based and started getting in original scripts. And maybe their budget grew because there are a lot more extras in scenes set in the city and this gives it a more exciting and realistic feel.
A problem that Banks had, along with Vera and Shetland, is that they were so sparsely populated that the drama seems more like a play, or one of those studio-bound programs redolent of the 1970s on British television. This series is more filmic and alive than the past series. I was surprised and enjoyed it a lot more than the previous series.