Apart from this truly cynical thought, I enjoyed Calling. It's structure reminded me of Sekaiichi Hatsukoi: we come across several stories of three pairs whose lives occasionally clash. It also means that there is no conclusion to any of these, so the overall enjoyment may be flawed.
The story's value lies in its novelty - I mean, it was my first time reading a (yaoi!) manga revolving around terrorist attacks in Japan and the corporation or whatever that fights against it, apparently. So we get to see lots of secrecy, suits, and bland/angry expressions after love confessions.
The sex scenes, however, are not the cohesion to stick the story together, and in itself, it's a good change of pace.
I was enjoying (again) the lack of angst, and was frowning at the cheesiness of the stories. I mean, it's as cheesy as it gets. If you are into over-the-top lovey-dovey inner monologues, then this is a worthwile shot.
Annnnd, the faces are pretty. Really pretty. I was staring at some of the panels for several minutes, because they were really to my liking. No big, sparkly eyes and sakura petals in the background, YAY!
