The first story was well done. The whole bit with Arthur, Buster, and D.W. trying to make a sand castle that would last a long time was nice and the last part with it being in the newspaper made for a very nice ending. D.W. has a new voice too.
The second story wasn't too good unfortunately. It felt very boring at parts and overall, the way Buster suddenly got so afraid of germs was stretching it and it just got annoying after a few minutes. So the first story was good but the second one was really disappointing. A decent start to season 11 though I was hoping for something better.