AI Revamp: vision and hearing detection revamped to adjust for time of day, weather, movement, indoors, flashlight, suppressor usage etc., AI more likely to use full auto, AI will sometimes briefly suppress the player's last known position when losing sight of player etc.
AI Gear: Border guards and the military can equip armor plates and helmets. Some enemies use rifle optics. Expect more accurate fire from them.
More enemies: slight increase to the number of active and total enemies, more randomized