Decent, but not good, is my verdict.
Making Aria even slightly more sympathetic (which is what they seemed to be trying to do with this DLC) kind of undermines her character, to me. And I don't particularly care what happens to Omega. It was a nice change of pace in ME2 from the bright shininess of the Citadel and showing the more downtrodden side of the galaxy, but Omega isn't a place I feel like fighting for, and I don't particularly find Cerberus very much fun to fight. Their pathetic new "let's walk in a straight line while getting shot in the head" mechs didn't do much to help in that regard.
The Adjutants were also extremely underwhelming. They were hyped up, everyone was scared ****less of them, they slaughtered a bunch of people... and then they turn out to be essentially easy-mode Banshees. *yawn* They weren't even all that scary to look at.
Now: the good. The gameplay is as good as ever, and I liked some of the vistas inside Omega (that mine shaft was damned impressive). It was fun seeing Harrot again, and I liked some of the NPC's milling around. I also liked that General Petrovsky commanded with some semblance of actual tactical capability. Those force fields were actually kind of cool. We finally get to see what female turians look like. Also, chess set.