You must be playing a different game than me then, because I'd be 100% in your corner if I could reproduce what you're seeing and... Aside from occasional lag that every gamer experiences on every game, I have a pristine experience in Black Ops.
For what it's worth, I can find you "Laggiest game on the Earth" threads on every major Multiplayer video game forum, ever. Halo, Call of Duty, Battlefield, Medal of Honor - they all got 'em. I'm not saying that to dismiss what you are saying; I'm telling you that each game's net code is different. Every other game might play perfectly for you, personally, but COD games don't. If that's the case, then it could be as simple as port forwarding or a router that handles NAT better. These are things our Customer Support team can help you identify.
If you think Black Ops is drastically different, it's most likely a perception caused by Theater mode and the over-awareness of this perceived disparity because of it. If not, then it is a technical error that I am confident Customer Support can help you with. It is not a bug in the game that we need to patch... If it were, we'd happily do so to end the debate

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(I wish I had a blue-in-the-face emoticon to choose from lol)