I like changing it up, but honestly I think we're past the point where small changes can remain compelling. Dexter has essentially returned to the life he had before getting married and all that, he just happens to have a kid to come home to now. The bigger problem though is the season arcs aren't personal for Dexter anymore. The only risk he seems to be getting into is due to him doing stupid stuff like trying to 'bond' with another serial killer (last three seasons).
I'd love for the season finale to be Dexter coming home from his climactic showdown with Edward James Olmos and getting arrested, with clues scattered through the season (only notable in retrospect) that someone has caught on and was investigating quietly the whole time.
The formula has to change, not just the window dressing.