Well, this, epic, final film was a first-rate conclusion. The historical back story using the same actors as the modern episodes was an excellent idea, particularly as I think (I would have to re-watch the whole series to be sure) that there were some connections between the modern characters played and the characters in the origin story that they played.
The story unfolded gradually and powerfully - with thematic connections to The Crucible and The Village in particular - with the historical setting seeming marvellously and grubbily real. The intersection between past and present was very well done - and even the modern pop song soundtrack was not as irritating as it has been in mnay other shows I have seen. What was once entertainingly and often satirically amusing is now a dreadful musical cliche I am afraid and it needs someone to re-boot the idea I think - or perhaps come up with a completely new musical approach.
I also very much .iked the fact, and the way, that there was a centrally important lesbian relationship (perhaps only suggested in the second film though) as an important plot element but was just a completely natural and unforced part of it.
So, a surprising and highly enjoyable trilogy - particularly as I was so dismissive of the first one which I think I may well need to revisit to re-evaluate. Looking back I see my main (absurd) complaint was that it was not what I expected!