Just finished the DLC, but it was a hard way for me.
First off, I'm from Poland, one of few countries, where LotSB is not supported. Well, I bought the DLC without knowing it, and when I found it out, I was angry as hell. Fortunately, I was able to download the digital version of my collectors edition (english one; I was playing with the original audio, so the language wasn't a real issue), which delayed playing the DLC for a few hours (at first, the EADM was pissing me off, because it didn't want to start, then, when finally it launched it was about 3 hours of downloading the ggame itself, then installing all my DLC - annoying).
*Spoilers warning*
As for the LotSB itself... it just rocks. The locations are superb, especialy the hull of the ship. The action is just as fast paced as ME2 ever gets. the conclusion of the DLC will have a huge impact on the third game, and I just wonder how 2 playthroughs of ME3 will differ, depending on whether you finished the DLC or didn't even buy it.
And the Shadow Broker itself is just one big piece of badass. Didn't expect a space ogre to be behind that kind of business. The fight with him was very rewarding, and I enjoyed it much.
Of course meeting with Liara again (and helping her) is a splendid addition to the game, and despite Liara is not my favorite ME1 character, this mission pack adds depth to the asari scientist, although I didn't like that she became so rythless.
the thing I found strange is the fight with the assassin. The story inicates that she is weakened at the moment of the fight, and she was more of a challenge than the Shadow Broker.
And I loved the humour, especially when Shepard reminded me about the Omni-gel in ME1, and the Legion Gamer profile is hilarious
I think that it is a must-have for any ME fan. Personally, I hope that the DLCs to come will be THAT good. If so, I won't hesitate one second to pay for them.