I really don't feel we can accuse it of losing its touch yet because the trilogy isn't even over. I mean, Halo, CoD, long running franchises you might be able to say that about, but I don't know if you can quite yet bring that out on ME yet.
That said, I did miss the lack of RPG elements that transferred from 1 to 2, and the simplification of Gameplay. Why? Because I was an Adept, that's why. Suddenly, I am missing some of my best powers, and the ones that replace them are crippled by comparison. In the first, I remember making my Singularity so powerful that it was able to suck up entire rooms full of enemies that I could then throw into a wall across the complex the moment it ended since all were so closely bunched up. What did I have in 2 in terms of strategy or depth?
If the target is on their final red bar of health, pull upwards, wait, then throw from underneath. If they are not at health bar, either warp or shoot.
There really was very little in terms of complexity that I could pull off, and the satisfaction of it all was hampered by the ease of shooting people into orbit. Seriously, I could do it so often in ME2, that performing it became routine. In ME1 when I was able to throw someone out of a combat arena, it was much rarer, and I had to make sure I was perfectly alinged to do it. That's why Virmire became the most entertaining section of the game because the open railings and such allowed you to hurl enemies into oceans if you got it right.
So yeah, while Soldier didn't really get effected, I felt as though almost every other class was, and not in a good way. It made it so I had less to do in the face of others, and what little I could do just got endlessly repeated because I never had the chance to change my strategy to something better in a certain context or situation.