Maybe it makes me weird but I actually quite liked the open ended nature of that finale. Did Takahashi eat Itou? Did she refuse? If she refused, did Itou stay with Takahashi in the Gobi or did she return to Japan, satisfyed at simply having gotten to meet her again or did Itou just wander off into the desert chasing a mirage that wasn't really there?
There are a few things I wish could have been elaborated upon. Ooki saw her friend being devoured and discovered the existence of monsters, how did that affect her? And what about Itou's grandmother, as I recall there were some implications that she knew more than she was letting on but aside from those, it was a great manga and a good ending in my mind. Enjoyed it overall.