Satisfaction is a relative term. Some people might enjoy the drama just fine on its own and be completly satisfied. Me, on the other hand needed that special episode to "finalize/finish/complete/" the story. Cherry on top, if u will. Great show, near perfect.The odd flying people kinda lost 0.5 in the rating :D
If you are like me and like a complete show and are completely satisfied only when the stoiry is fully done you need to watch the special after the final episode.