I apologise to the devs that there is little more I can give on this one but I have played a ton of multiplayer in the last couple of weeks and there is definitely an issue that seems somehow linked to network activity (or updating/syncing other player data perhaps?) that results in the game freezing with that horrible droning sound for about five seconds and the console returning to home screen. At one point during peak time this was happening so often that I couldn't complete a single game without crashing, maybe once every fifteen minutes or so. I even made sure that the XBox was sitting on it's own and well ventilated, initally thinking it may be overheating, but it happened at various points that did not imply CPU or GFX load. I believe it also explains the other issue I have seen which always surprised me how mid game, the host would simply leave. In the few occasions where we had set up a party outside of the game, they reported they crashed and were bumped out and also experienced it a lot.
Obviously I know it's hard to chase down a ghost but if it is experienced by so many players online, I can't believe it isn't repeatable by devs on a debug platform. Would really appreciate you guys spend a few hours on MP to track this bugger down for us.