I thought armor protection worked amazingly in ME2 on the most difficult levels (in which all enemies had some kind of armor).
I remember one of the best moments I had with biotics in ME2, in Mordin's loyalty mission. I was playing a sentinel, with Mordin and Miranda in my party. There was that part in the mission where you go down the hospital, it was a big square space empty in the middle and in that part a few Krogans rush you. So here came the Krogan with its armor. I used Mordin's incendiary attack and Miranda's warp and it almost took the armor away, nothing that a couple of shots from my pistol wouldn't finish. Then, with the Krogan vulnerable to biotic attacks I used a throw, only that I aimed it slight below the enemy, so the power arched upward. The krogan was pushed back and upward, not that much, but just enough so it hit the fence in the middle and tipped to the pit, falling to his death. It was a thing of beauty.
And this show ME2's combat working at its best. A careful choice of squadmates was essential (Mordin was forced on the party, but choosing another character that could destroy armor was essential), the well use of powers (to take away the armor), and the elegant use of a biotic power. If this was ME3, there would be a tech explosion after Miranda warp and a Biotic detonation after Shepard's throw. So instead of a killing with surgery precision, it would be a mess explosions.
Also, 3.000.000 for the announcement trailer. Good.