I really think it could be massively important to implement tactics properly this year from what I have gathered in the demo. Which is brilliant stuff if it's the case.
For example, IRL Barce and Real will just tear you a new hole if you try and match them attack for attack or to press them high up the pitch. They are simply too good at finding space and eventually through passing and quality of player they will just glide through the midfield. This is how it should be IMO. Against the top teams, even as a decent team yourself, I think it paramount that you need to adjust your tactics. And this is where this season could be the first season since the old PES games that I need to really do some homework and look deeply into combatting the CPU through tactics.
For example, yesterday I got beaten 3-1 v Barce as Athletic. I then played a game and dropped my defensive line deeper, had two DMF's, and positioned players narrower. This seemed to combat their silky players. They had much more possession, ultimately more territory and still looked the better side but I was able to stem their fluid attacks better, the game ended 50% each in possession and 0-0.
Also the pressure slider I believe is very key to containing the CPU. I am of the opinion that anything high in this years game on Superstar mode against the top teams is suicide, unless you play a Barce type game with everyone pressing (front front to back) high up the pitch. The pressure slider drags midfielders out of position and towards players, and if they are gifted ones they will simply pass through the midfield.
I really believe also that this years PES relies a lot more on the player (ie the human) having the 'overall picture' in their minds eye as moves are taking shape. It is crucial on Superstar to be able to pick up runs and dummy runs, and to shift players across to and fro. The use of player switching (to the CPU sometimes) to contain danger is also a biggy I think. In my experience, you need your team to play as a unit much more realistically this year, this forces the CPU into possession football and exploring different avenues than just the plough down the middle philosophy.
I'm afraid though it's very much like last year and for me, there's no way I can play 4/5 games on the bounce with the timer back to 15 minutes, it relies too heavily on utmost concentration. I believe I will be best suited to play 1/2 games at a time. My results went from very good at the start of last nights session to bloody awful when I got tired. I think it's a punisher again this year lads!