I really loved this series overall. The acting is excellent, the plot is winding and clever, and much of it is quite funny. I was consistently drawn in, entertained, and curious what would happen next.
The ride does, however, become a bit bumpy towards the end. The problems are mainly related in some way to religion, both in an utterly nonsensical conspiracy and in some overt supernatural elements that are hinted at throughout the series but are ramped up far too much in the latter part.
Then there's the end, which is both predictable and unsatisfying. Even though this was a miniseries, it's clear that the intention was to have a second season, so they left a mystery unanswered one or two threads loose. This would have been unsatisfying even if a second season were coming, but it's not, which makes it *super* annoying. (Hopefully at some point the developers will give an interview and fill in the blanks.)
If not for the ending, I would have given this a 9 rating instead of an 8. But I've seen far more frustrating finales, so I didn't feel the ending entirely ruined the series; it just made it weaker than it should have been.