It's good. Olivia Colman as Elizabeth is superb, just as you would expect if you know her work. There is another actor from Broadchurch present, playing a very different role; I'll let that be a surprise. Helena Bonham-Carter is really a little too glamorously beautiful as Margaret, but of course her acting is first-rate.
This season takes the story into roughly the mid-1970s. It's a little frustrating, never knowing how much of the story is gossip and hearsay and how much is certainly true. I assume that all public appearances and speeches and so forth are accurate, and that private conversations are invented, but that leaves a big middle area that could be roughly accurate or wildly wrong--portraits of relationships and so forth. I suppose the filmmakers didn't go too far out on any limbs, though I figure they probably turned up the elements that lend themselves to a soap-opera-ish treatment.
Here's the trailer:
I really must find out the name of the music that's playing at the end of the last episode (not heard in the trailer).
I sort of dread series 4, which will have to wade into the Charles-Diana misery.