I really wanted to like this series and it was... just okay.
The general problems: The pacing was horribly erratic, feeling overly rushed in some places and dragging in others. Information was repeated for no reason (e.g. Peter has the exact same conversation with both his mother and his cousin about going to school with an upir "but I don't think he knows what he is") or cropped up suddenly just to be dropped (the whole "other name" thing) or was just skipped over. Accents are all over the place. It's fairly obvious who the killer is before the "big reveal" and there's a couple plot holes big enough to drive a semi-truck through. Finally, the leadup to the next season that is way too long.
And, while I should have been expecting it from Eli Roth, it felt like the story was constantly being interrupted for sex and gore.
This is a series where the parts are greater than the whole. A mystery, supernatural vs science, messed-up people trying to interact. Some excellent acting in parts. Some real poignant moments. A pity that they couldn't sustain those highlights through the whole thing.
I'm sure some people will argue that some of the issues (plot holes, etc) will likely be addressed in the next season, since this was based on a trilogy of which only the first book has been published. But since this season failed to make me all that interested in a second season, I'm not sure that's a good thing.