The problem is that it is a Mass Effect game without any of the nostalgia, which means that everything is new while feeling very similar at the same time.
To be honest, it isn't like Mass Effect 1, where I was amazed at the Citadel, but that is because I had already seen a lot of the same things in Mass Effect 1.
I am really enjoying the game, the changes to the movement system with the jump pack really improves combat and adds a lot of verticality to the levels.
A lot of people are complaining about the animations, though IMHO they are no worse that what I have seen in other RPGs. The rest of the game looks so good it just makes the animations more noticeable.
A lot of the complaints that I have seen could have been aimed at any Mass Effect game, like repetitive gameplay, bad animations and occasionally wooden dialogue. I have not played the whole game, so I cannot comment fully on the story.