The lag sometimes has nothing to do with your PC or Connection though. My ping is usually around 19 to 30. My PC is pretty darn good and it's clean as a whistle and D-Fragged.
Sometimes when i'm playing... THE GAME WILL FREEZE.. for like a second... then resume... THEN FREEZE then resume... It' royally sucks. It happens to me often in a helicopter... It's random. Some servers it happens... Some it doesn't...
Last night I was in a "Strike" server only. There were 42 players. It was absolutely insane... sooo much fun. Anyway... I was just waiting for FREEZES and lag like crazy... I didn't experience hardly any...