I'm enjoying it, mostly. It lacks the flavour of the novels (as often diffuse and splurgy as they are piercing and striking), but it gets most of the key incidents in and Stoppard has lifted a fair quantity of actual dialogue straight from Ford. If the WW1 scenes have something of the feel of Blackadder Goes Forth that's not necessarily Stoppard's fault. There's something of that in the original. And Benedict Cumberbatch and Rebecca Hall both give excellent performances, although the Bagpuss voice Cumberbatch adopts for Tietjens is a little groany-moany for my taste.
The ways in which the adaptation differs from the original novels interest me, though. I can see that a certain amount of compression and elision is necessary when translating a book into a televisual or filmic idiom; but some of the changes seem odd. In Ford's novels, for instance, Christopher Tietjens is fat (he's often compared to a filled sack). Cumberbatch is not fat. Tietjens' older brother Mark is more of a dunderhead in the novels; perhaps Rupert Everett didn't fancy playing him that way. But in the novel Mark is the oldest of four (Christopher the youngest) and the two middle brothers are killed in the war. Cutting them entirely from the adaptation perhaps sacrifices the emotional force of Chris's decision to enlist to the virtues of streamlining the story. Tietjens senior commits suicide, believing that his youngest son has gone to the devil -- fathered a child on the daughter of his friend and so on. In Stoppard's screenplay he thinks this because Mark sits down with him and tells him, which (a) paints Mark in a rather brutal light, and (b) makes his subsequent carefree behaviour seem extraordinarily heartless and uncaring. In Ford's novel it's another character (I can't remember his name) who tells Tietjens Senior the rumours about his son. Again, not sure why Stoppard made that change.
The novel also includes a good deal of Chris's internal life, from which we discover that he's a lot more hesitant, and conflicted, about the moral stands to duty he makes. Without them his character comes over more marionetteish. And in the long -- improbably long, but there you go -- conversation he has with General Campion on the western front (at the end of No More Parades, I think) Tietjens says something about how the key to his character is that he was a public schoolboy who actually believed all the stuff they told him at school, and who hasn't properly grown up. I'm not sure why Stoppard cut that bit out, unless it's because it would tend to diminish Tietjen's principled stand in our modern eyes.