I have finished it now.
Gameplay was more of the same, pretty much (though, honestly, what were you expecting?). However, that's not its strong point.
See, I love this sort of thing. Revelations, backstory, fleshing out of the universe.
And with this we finally have:
the full backstory of the Reapers. Guess Sovereign's claim of them being eternal and having no beginning was a lie, but then I kind of thought it was the moment I heard it.
The only thing is, yeah, if you've played the Extended Cut DLC, there's not a lot really earth-shattering. It pretty much confirms what we already knew, albeit in greater detail. It does, however, introduce something new to the ME universe, and another 500 or so War Assets if you want them.