Halo 4 was great, but could have been handled a lot better in my opinion. The only real fuck up was that the main villain was introduced in one of the novels, so the Diadect showing up out of no where was a little jarring.
Aside from that, this is the first Halo game since the first that seems to give a fuck about the plot. 343 Studios won me over in the first 10 minutes with that, and they kept it up the entire game, so I'm extremely excited to see what they do now. Also, I'm going to get some flak for this, more then likely, but fuck it. I want more Flood.
Yes, I love the Flood, both from a story/lore standpoint and a gameplay standpoint. I want to see what 343 actually does with the Flood storyline, considering how important it is to the Halo universe and how poorly it's been handled with Bungie.