Apart from a couple of 'slow' parts and some rather bad acting by the Lady of the Manor, I thought this episode wasexcellent. I had already figured out that it would be Lady Sybil who died but I found the event poignant, perhaps more for her talk with Mary before her death than her death itself.
I believe it was Robert's pompous arrogance and stupidity which indirectly led to Sybil's death, so I find myself agreeing with Cora on that point. Thomas's reaction was surprising but gratifying. Carson was just plain ridiculous about the whole 'Ethel at Crawley House' thing, but good for Mrs. Patmore for seeing it for what it was.
I don't like to write too much in a review for a show which has yet to be seen in the US so I will say nothing more except can we please either deal with the whole Bates issue or get rid of him? His storyline, once poignant, has become meaningless. As for Daisy, she needs a good shake. I'm certain the rest of the series will be equally excellent.