As a long time fan of the series, both old and new, I would say that the 9th series is an improvement upon the prior season. Moffat has a leaning toward plot over character, and so, a series full of 2-parters lets his storytelling shine better than in prior seasons. That said, no series is perfect, and there are a few clunkers this season. But, it is overall an improvement in quality. The set itself is an improvement as well, with more special features and commentaries than the previous series sets. It also contains 2 holiday specials given the timing of the series and how long we will have to wait for the next series to air. Overall, an improvement all around.