Kasumi is an awesome character download for ME2 and has a very cool loyalty mission. Also did the DL mission where you get the hammerhead so far, but haven't done anything with it after the first mission with it.
I know everyone HATED the Mako, but I never really had a problem with it. And everyone seems to think the Hammerhead is like an uber-vehicle, I just think it's on the same level as the Mako. Both of them are cool, I don't really care for one more than the other.
Kasumi though is just awesome. Definitely one of my favorite characters from ME2 along with Thane, Jack, Legion, and Grunt. Some of her abilities are just a lot of fun to have around.
Might get into Overlord and the rest of firewalker tonight.