Something that clarified my feelings about Hickman was in an interview he did recently where he talked about how he hates episodic TV shows - i.e. shows where episodes tell a complete story that gets resolved in an hour. I feel like as a writer he is all about the long term and doesn't care that much about telling a satisfying story in the short term. When I pick up one of his comics I usually feel like it's just teasing exciting stuff that may or may not happen toward the end of his run, but I want to have some excitement right now.
However, as de facto co-editor of the X-Men line he's made it more interesting than it has been in a long time by forcing the writers to get away from the usual X-men clichés and finding a status quo that allows them to combine a new direction with old-school character nostalgia. So I can't argue with the decision to put him in charge.