I liked Catherine until S5, then I hated her. Started to like her again after that but then when she became supervisor again, the hate returned. They just can't writer her as a supervisor without making her full of herself.

ETA: I think some of the characters started going down hill in S5 (Greg as well as Catherine) but Brass didn't start his decline until last year, when they completely ignored him. He lost his snark and spark.