There is a network adapter setting called Throughput booster.

Turn that bad boy on. It'll make your machine get more preference in the network. Game felt buttery smooth after I turned it on.

Shots were registering better, game didn't feel like it was a half a second behind anymore.

Might not work for everyone. But it helped in my case on a congested network.

Even if it doesn't particularly help with the gaming side, it should theoretically help with DL speeds.