I have received both the PS4 and the PS3 version. Black Flag plays terrific on the PS3. Clear the game looks on the next-gen consoles (PS4 / Xbox One) a little better and the load times are reduced slightly but that's the game on the PS3 not diminish.
What I particularly like about Black Flag, the free space is the player enjoys. The player has the opportunity to forget the real story for a while and make what he just feels like. Compared to the previous parts of the Assassin's Creed series Black Flag has a lot more "free" game content.
For example, you can watch just grab your ship and explore more than 50 places in the Caribbean. It works continuously without any additional loading time.
Furthermore, I find the combination of video and gameplay in this part exceptionally well done. The rehearsed video sequences look like real little film portions and not as ported in-game sequences.
These film sections allow the player more to participate in the story.
The gameplay has been significantly purified in Black Flag by Ubi Soft. For example, jumps and climbs her now with the same button. Run her against a wall, the character begins to climb. I like these little innovations really good.
I also noticed that the fighting in Black Flag take significantly longer to complete. The entire combat system has been reworked and made more sophisticated. The character Edward holds less than all predecessors and also the healing potions were abolished.
Overall, I like Assassin's Creed 4: Black Flag very good. Boredom is not through the open-plan game world. The missions are exciting and a lot of fun. The pirate flair has promised me very personally.
Buy yourself the game, you will have a lot of fun with it!