Be it ever so humble, there's no place like a secret impenetrable lair
Unlike Overlord, the Lair of the Shadow Broker DLC story sticks closely to existing Mass Effect lore.
In fact, it's part of the setup for Mass Effect 3, showing how Liara went from investigating the Shadow Broker to being the Shadow Broker. And that's about it.
The mission starts with some intrigue, Liara going dark and Shepard following her trail ... but it isn't long before you're just mowing down wave after wave of goons on your way to the Shadow Broker's, uh, lair.
Ultimately this DLC's story feels like a two minute cutscene stretched into two hours of gameplay. While that gameplay isn't "bad," per se, it's unremarkable; more of the same stuff you're already doing in Mass Effect 2.
And since "Liara is the Shadow Broker" is such a minor plot point in the third game, this DLC's narrative payoff doesn't end up feeling very meaningful.
Better than: Mass Effect 2: Zaeed - The Price of Revenge
Not as good as: Mass Effect 2: Kasumi - Stolen Memory
Meeting a Yahg was pretty neat: now I'm disappointed that they didn't play a bigger part in the series.