I fear that my answer on this score is brief, and probably not terribly engaging. I didn't like Season 3 much at all, and I know absolutely nothing about Season 4. I love Seasons 1 and 2, still, and that's about where the scope of what I count as canon ends. The screenwriting turned too careless for my taste in Season 3; I feel like they're mocking their audience, and not kindly, either. I have better things to do with my time on the television front (my most recent hours-spent-watching-things investments have been In the Flesh and Six Feet Under, and I haven't been disappointed).