Ok, I've only played a few games against another person (my roommate plays against me in my franchise if he likes the team I'm playing that week), but I've noticed that the games I play against him are much better than ones against the CPU.
I started up a Cowboys Franchise and the first game they have is against the Bucs (his favorite team), so he took control of the Bucs and in 3 plays I saw 4 animations that I had never seen while playing many seasons' worth of games in various franchises. I saw a WR jump up and make a play on the ball instead of waiting while the DB made a play. I saw the Bucs LT demolish Demarcus Ware and ride him into the ground when Ware tried to dip his shoulder and speed by the LT. I saw Felix Jones do a contact spin move (spin right as you make contact, before the defender can get a good grip).
Also, pancakes actually happen in Human/Human games. Usually even my good run-blocking OL would come up with 1-3 pancakes between them, but against my roomate they'll rack up 10-15 as a unit. Leonard Davis and Flozell Adams are usually the main guys, but Witten and Lorenzo Neal will usually get one every now and then.
Has anyone else noticed that games agianst another person are better than ones against the CPU, and is there any way we can get the Human v Human gameplay into a Human v CPU game? Maybe start the game with 2 controllers and then remove one of them after the coin flip?