I never finished the third one. I kinda want to revisit and finish the trilogy sometime. I remember enjoying the RPG elements but looking back on it, it really glorifies the military, you're basically the space CIA if I remember right. You also team up with Garrus, who's a vigilante cop and the Space Fascist in the third one, whose genocidal racism is treated like "haha he's like your racist grampa lol".
Great games. Expecting good politics in your AAA titles seems like a recipe for disappointment.