I’ve played a few matches in Halo 4 within the Master Chief Collection, and I got to say, this game is running fantastically (better than on the 360). It feels great and responsive and looks incredible. I noticed the kill cam issues from the 360 have been sorted as well; 343 did a wonderful job porting/upgrading this game.
That said, the only problems I noticed were with the audio. My Carbine would occasionally go completely silent until I respawned. In another instance, all I could hear was the ambient background noises, but again, that sorted itself out upon my death. And lastly, Jeff was particularly quiet when I earned a “double kill”; the medal showed up, with the text on screen, but there was no announcement.
This probably isn’t high on the agenda, but it seems to me that the only problems with Halo 4 are the occasional audio bug (that, and I miss my Mark V … )