I thought Ellis was just way too campy and I agree wholeheartedly with his mention in EW's Top 20 Most Annoying TV Characters list. I just felt they never knew what to do with him, he got a lot better towards the end (I enjoyed his confrontation scene with Anjelica Huston) but it was too little, too late.
The actor who played Dev was good (and super hot) but he had a terrible role and like most of you have already said, he had no purpose and it made no sense that he would be with Karen.
I truly hope they re-conceive the show, I think both Leo and Brian D'Arcy James need to go, I don't think James and Debra Messing have any sort of chemistry. They also need to figure out how to write Karen as an interesting character, I got the whole Norma Jean thing that they were going for with her character, but they seemed to have forgotten that Norma Jean always had it in her to become Marilyn, something I don't think Katharine McPhee or the writers were ever able to portray successfully.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"