Great 1st episode - Good 2nd episode - Head Scratching 3rd
The first episode was really well done and captured much of the despair and terror of the novel's opening. The second episode was well done, but lost steam as it began to stray farther from the novel. The third episode was a head-scratcher. It wasn't bad, but also not entirely successful. It certainly had the Moffat/Gattis feel.
While I enjoyed the series, I think my favorite scene came in the third episode when....
SPOILER ALERT -- SPOILER ALERT
...Dr. Zoe Van Helsing jumped up on the table, ran and leaped for the curtains. This was a direct "steal" from Horror of Dracula (American title) and it made me cheer!