Well, after more than 60 hours in the game and after finally managed to play co-op with my friends (just in case you have the same problem: I couldnt connect to co-op at all, the fix came from Techland, sent to a friend of mine was to delete some of my steam friends, i had more than 300 friends, i have deleted some and the co-op part started working), i can say that this game is what i have expected after the first Dying Light, which was one of my favorite game.
The gameplay is smooth with new weapons and gadgets, the combat system is slightly better and well improved, the story line is good, not wow but good, (we can stand and wait now for the third one :D), i've finished the main story and now i'm playing the side missions, there are thousands of them lol, the graphics are great, sounds and effects are good, i had some lost sounds while playing co-op which was disturbing and needed to restart the game.
So, for me Dying Light 2 will be one of the best this year and ill recommend it, to anyone that played and enjoyed the first one.