I prefer the ACR with the silencer and grenade launcher with the mp9 silenced as a backup. I also like using the riot shield with the silenced mp9 and sleight of hand pro, gives me the lols when I do better than half my team using that setup.
I prefer to use speed with the shield so I can run faster. I use sleight of hand, assassin, and dead silence and most times they don't even see me coming. Like tonight I wasn't doing good in hctdm with the acr so I switched to the riot shield and first game I went 11-13 and was second best on my team. My best game tonight with the shield was 8-1 and I killed the same guy 5 times in different spots lol.