I think the one thing I dislike most about Grimm is the fact that the hero is a cop. That's a bit to formulaic. But I'm hoping he'll lose his job soon, and then things may get more interesting. (Since his Partner is a regular, it's unlikely, I know, but we'll see.)
And yes, no chemistry with the girlfriend - but I'm pretty sure she'll turn out to be not human. Or she gets killed. Either way, I doubt she'll stay.