TL;DR : Halo 5’s look mechanics (nothing to do with aim assist or magnetism) are somehow tied to connection quality making it so aiming can feel great one game and awful the next.
Before I start know that some will have run into this problem more than others. If you live in the US and search solo or warzone you won’t have noticed it as often because the game has a much easier time finding lobbies that are on closer servers to you.
However, if you live overseas or play arena at a higher level this becomes a very noticeable issue and is downright frustrating because while the aiming can feel crisp one game allowing you to land your shots well the next could place you on a server farther away making it feel like your looking around under water with how sluggish it feels. So then not only do you have to deal with the usual problems of the host not being that great for you (headshots not registering as consistently etc) you also have to deal with it being harder to aim in general. This puts you at a sizable disadvantage with how fast paced Halo 5 plays.
I’m really not sure how this is a thing and would love if anyone with more technical knowledge could explain why it’s like this. Sure we had to deal with lag in all previous Halo games but the actual look mechanics were never affected like this. Also, unless I’m miss remembering the beta didn’t have this problem either so something changed in the months between the beta and release. Even the pros have touched on it saying how they need to decrease their sensitivity by a good amount with playing on lan because it’s so different. I remember at one point on Lethuls stream he joked that he can only use the shotgun well on lan because it feels so much heavier online.
This needs to get more recognition because it’s maddening at times with how inconsistent the aiming can be. I play on a 2ms monitor but it’ll suddenly feel like I’m playing on a TV with 100ms input lag. I’m not sure if this is something that can be fixed with a patch, but if so I really hope that 343 will look into it.