For many, including myself, this is the season that "The Simpsons" jumped the shark, the quality of the episodes take a noticeable decline and although there are many funny moments in the season it is let down by poor writing that doesn't live up to previous seasons.
The "Treehouse of Horror" halloween episodes are always entertaining and that is no exception here and the 200th episode "Trash of the Titans" is also very entertaining, mainly because it features the Irish rock band U2. Other than that the stand out episodes are few and far between, giving the season an, unfortunately, entirely forgettable feel.
In terms of Extras the boxset is well on par with previous releases, commentaries, deleted scenes and artwork in abundance, certainly no complaints in this department.
Overall Season 9 is still worth a look but don't set your expectations too high, the classic feel and quality of episodes seen through the first 8 years is not here, however much it pains me to say it.