Think you are focusing on people with poor PCs/connections too much when you start saying that maybe it's other players bad PCs that are causing NPCs to lag. Yes connection is a factor, but its been undeniably proven til now that the servers suffer some serious hitching problems pretty much every raid regardless of where you are or how good your connection is.

The servers are either overloaded or need some serious optimisation work. When you play in a squad you can see most raids at the start you are desyncing/teleporting around. Certain maps, if I run into someone in the first 45 seconds (Like Reserve), it's a guaranteed ultra laggy fight.

My theory was always that it's laggy at the start as loot is being spawned as players all run into loot areas, but I'm finding servers are getting incredibly unstable and laggy even late into the game.

Last week I had several Interchange games last week where after about 25 minutes in the server started becoming unbearably laggy and both times it got me killed. Massive delays on trying to loot or interact with gear, throwing grenades making them appear at your feet etc (Actually killed me one of the times...Tried to throw a grenade down an open corridor only to have it explode on me and kill me)

This wipe especially had far far more situations where I or a buddy dies to someone close by before we even hear the gunshots as well.