I'm not using the term "mission packs" or "DLC" in this post as I feel it perpetuates the wrong mindset and I want to avoid it as best I can. Volition, I want a new campaign. Something more than 30 minutes of gameplay, I want an expansion pack!
None of the current items for sale satisfy that desire at all. Most of it is just costumes and weapons, but they're useless if there's nothing to do with them, which there isn't once you beat the game. How the saints saved Christmas would've been wonderful as a full on expansion pack, filled to the brim with Meaty content as well as holiday cheer. However, as it stands, it's just a set of short, pretty forgettable missions that, while still filled to the brim with holiday cheer, is but a mere shadow of what it could have been. In general, as someone who's played all four games, I feel that the purchasable post-release content for every one of them has been lackluster.
Personally, I hope you guys stop making small things like costume packs and the like such a huge priority and focus more on proper expansions that keeps the player's attention.
there you go, my two cents.