I liked seeing Kevin again, and I didn't mind that he was sent up to heaven so quickly. What did bother me was the line where he says, "I always trusted you guys," because it wasn't true. In season 8, he takes his mom and goes into hiding because he doesn't trust the Winchesters not to hurt her. He later changes his mind and starts trusting them again, but the line in 11x21 still bugged me.