I think Professional difficulty is the way to go for the Demo. Already seen the CPU properly use the Attack/Def levels. They are changing their gameplan of those levels depending on who they face. I think the higher difficulties are too sensitive to those levels, which is why they appear so manic and hyperactive to switch to them.
On Pro difficulty, the CPU actually plays the right way, relevant to the Att/Def levels. And no, it's not very easy to beat them because they are not giving up their spaces like they do on Top Player and Superstar. A press is a proper press where the players step into their zones, relevant to where the ball is, and then pounce on the player, but not to the point they swarm with 3:1.
Playing right now.
https://gaming.youtube.com/user/Matt10L/live