That bid ole patch accompanying the DLC brought shiny new things including the ability to rest weapons on surfaces and deploy bipods to improve accuracy, making recoil feel more powerful and real, making AI respond to suppressive fire, improving the sound by changing it in different environments, boshing in a new multiplayer mode, adding a scenario where you roll around firing from vehicles, and oodles more. Heaven help me, I do enjoy shooty vehicle sections in games. This week they released the shooty Marksmen DLC, which adds more guns, scopes, ghillie suits, firing drills, and other things that go 'bang!' They also rolled out a hearty patch which improves the fundamentals of how guns work, and adds new bits and pieces including a scenario focused on feeling cool rolling around firing guns from moving vehicles.
When makers Bohemia Interactive sell new odds and ends for cash money, they've also released free updates adding related extras for all.