I agree with everyone, it's a must have mod. It takes a while to setup the installation, you need to be trough checking out the conflicts list, and the conversion system. I'd say overall it took me 3 hours to setup the whole install, but it's totally worth it. If you do it right you get close to no bugs/glitches, which is good because you can focus on actually playing the game.
What I like most is how, if you mod it right, DC is really 10 times more dangerous than the Mojave, and you get to really experience how Fallout 3 should have been in every way, things like Project Nevada or all the gameplay mods for NV make it really awesome. Don't get me wrong , Fallout 3 well modded is pretty fun, but this is just awesome.
Plus, after completing DC and moving on to LA; you really feel it's justified for your character to be an absolute badass, since he has years of experience and accomplishments behind, even if he doesn't remember.
Overall, great mod.