Game play is butter smooth on my end, but I'll have a burp / glitch every now and then in Multi-Player (regardless of settings). I've noticed one thing though, It's not usually when a ton of stuff is going on visually for me... It happens occasionally during sound FX, like when team-mate blows up the objective.
(1). I was running in room alone (no windows), but was lagged when the explosion SND-FX went off even though I'm not displaying the visual FX of explosion.
(2). I was taking cover behind wall, a team-mat nades a room across the street which resulted in very brief lag/hitch (about 1/10th of a second). Again, I'm not viewing the explosion / debris visual FX.