From Ashes is a single mission, which isn't anything special. However, it adds a permanent squad member, Javik, that I at least believe should have been in the game to begin with. Javik has as much dialogue as any other character. It also adds a new assault rifle.
Leviathan adds three missions, and it's story reveals the origins of the reapers. It also ties into the new Extended Cut endings.
Speaking of the EC endings, they fix a lot of the issues with the original endings. Just not all of them. But it is an improvement.
I haven't bothered to get Omega yet, and probably won't until it's either on sale, or I find a job that pays sufficiently that I no longer care about the price. $15 is too much for something that will only take me a few hours, and I'll probably only play two or three times. --- There are 10 types of people in the world. Those that know binary, and those that don't. Gamertag: Talon Omega
I enjoyed Omega, it felt like the ME3 equivalent of Overlord in terms of story scope. It's no Shadow Broker, but it was better than Pinnacle Station, not that that's saying much. --- GT: MikkoMetevinio; Steam: sirisaxman "Yes sir, a local airborne insurgency has infiltrated the U.S. zone designated as my pants, sir!" - Sgt. Lugo