I like that Strong Sad had brightened up a bit throughout the years. He used to simply be the depressed guy, but now he's also the smart guy and the overall talented-at-random-things-guy. XD
For instance; he can do calligraphy, knows that a jabillion is not an actual unit of measure, can draw a kick-awesome dragon, writes poetry, and can play the guitar.
I feel as though the characters are getting a little more complex; as though their personalities are expanding....*furrows brow and nods while stoking chin*