Bulman seems to be a little known/remembered series, but was popular enough at the time (enough to be shown in the U.S. on PBS), and has had tremendous influence on subsequent - but, alas, lesser - detective/police/crime dramas.
The series was unique, but not in the sense that it was so far superior to predecessors or contemporaries. No, Bulman was one of several excellent detective/police/crime dramas to come out of the seventies and eighties, including The Sweeney and Minder. Each show had a very unique concept, and featured memorable and real characters played by amazingly talented actors. The one characteristic all these series shared was true grit - they reflected real toughness, machismo, and cynicism, as opposed to the ridiculous posing one sees in modern cop dramas.
Anyone who thinks modern programs like From Ashes to Ashes or Life on Mars are so wonderful should watch or re-watch any one of those afore-mentioned series. A direct comparison would be evidence that, where television is concerned, quality has suffered over time. Sure production values have improved, but writing and performance have greatly suffered. Prime Suspect is the one exception I can think of.
While television today is primarily all style and no substance, series like Bulman proved that great substance produces remarkable style.
