Preferred Rooms at Pop Century

I always like a better room, so I was curious if I should have any interest in the preferred rooms at Disney's Pop Century. My conclusion is they're not worth it for me. I actually like DisneyZane's logic. Which led me to a couple of useful articles:

Pop Century Preferred Rooms on WorthyPosts and
Are Pop Century Preferred Rooms Worth the Money on the Pop Century fan site.

I still can't tell whether you have to pay extra for a King Room though.