The whole point of the story is that Ross is continuously torn between Elizabeth, a rarified, delicate flower from an ancient family, and Demelza who is her polar opposite, hard working, earthy, natural.
His sense of social justice meant he had to marry Demelza after he'd had his way with her, as otherwise he would be no better than the others of his social class who have no regard for the downtrodden masses. He was also hoping that this new passion would dampen his ardour for his old love. We'll see how that pans out!
Way back someone said that they couldn't see Elizabeth at Nampara as it would be beneath her. I think that's wrong - she comes across as a trapped bird who, given the chance, would be more wild and abandoned (hence the scene with the chickens), in the same way Demelza will have to learn to move in 'society'. All about class innit.
I liked the scene between Elizabeth and Demelza with the flowers. So much passed between them unsaid in that scene, and it was very true to the book. I wonder if a lot of the criticism of Elizabeth comes from the way the character is written. She isn't free to express herself, so comes across as cold and distant - in the book you get to hear her thoughts and so maybe is more sympathetic.
Still not really 'believing' it, and agree it seems to be moving too fast. If they have been given 5 series it seems a bit unnecessary. Enjoyed Robin Ellis' cameo though.
Realising that i now sound like one of those dreary women who want to talk about the plot i would like to say that the scything scene was acceptable! Sorry for the ramble - only watched it last night and there was lots of stuff to comment on.