Sometimes it's bad- like, the fact that Keller moved from utterly terrified and socially crippled to brave and spunky without enough of an arc. But sometimes.... I see all these people complain about how utterly inconsistent and contradictory McKay is, and I ADORE that about him. It's all one step forward and two steps back and sometimes it's like he makes a BREAKTHROUGH and then he's exactly like he was the very next episode. I don't know why it makes him such a compelling character to me when it's caused by bad writing, but... it WORKS for me.