Deb and Dexter's characters changed from season 3 (J Smits' season) to season 4 (guest J Lithgow). Deborah's use of the f-word became so frequent and not used comically or imaginatively as it had been - and Dexter losing his cool? cussing? Sooo not Dexter. I much prefer the never anxious, always-sure-of-himself Dex that took on Miguel Prado. Somehow this became so distracting for me - I was almost counting how many times Deb said "fuck" per scene.