I would not judge the story and choice making part of the game from the demo. I am quite sure they heavily cut this part to not spoil too much stuff.
I agree though about the clunkiness of the cover system in the second part, I ended up switching cover quite often while trying to get out of it.
Appart from that it seems quite similar in terms of mechanics to ME2.
There is one thing I find totally stupid though and its the "game-mode" choice if I could call it like that.
I don't understand why they wasted time programing the "F the story I just want to shoot stuff" mode and the "I want a totally unchallenging game experience so I can concentrate 100% on the story" mode.
ME is an FPS-RPG with story and moral choices occupying an important part.
If you remove one of these things its just not quite a ME game anymore.