Man the Guns is without a doubt in my mind the best DLC made for HoI4 so far. It is rich in mechanics that will nudge the game into a much needed realistic direction. The large modding potential the new mechanics will introduce is something I'm also excited for. And while I'm not a huge fan of most alt-history stuff in this game, I've noticed PDX has began fleshing the alt-paths out more and more, making them a little bit more plausible (e.g. England gradually flipping fascist through marches, rather than overnight with little cost). The "go with Churchill and oppose Hitler early" storyline is probably the most plausible alternate path PDX has done so far and one I'm actually looking forward to trying.