I'm a new Mass Effect player...
The character lip synch is off but the action and interface is actually pretty cool. The camera a ND mechanics works well enough but when things get hectic, it's harder to smoothly get into proper cover.
The story and world is absolutely stunning.
When an enemy runs up on you, its a pain to turn and melee. Might just do a quick jump with a ground pound from now on.
The older games had a "stick to cover" system which didn't work when you wanted to just move around freely. Plus shooting and movement is much more fluid. Downside to the new combat right now is you can't control squadmate powers which was an essential strategy on harder difficulties, we'll see how good the AI is to supplement this.
Liam throws grenades against his cover all the time. I wouldn't have hope with this.