So, earlier today Square Enix held this conference evaluating the Duscae demo feedback by Japanese, North American and European players.
Seems like the lock-on system, the camera, the dumb AI and the poor frame rate were the main points of critique by fans. Tabata promised to look into all of this and some of these points are already being improved right now.
In each region there was one concern, that was named particularly often and thus came to the attention of Square Enix.
NA: Noctis' English voice sounded unfitting for the character. Even Tabata joked, he sounded like Batman.

This is already being fixed. Noctis will sound younger and more approachable in the final game.
Europe: Cindy is too sexualized. While Square Enix pretended not to see it that way (she is just being energetic and outgoing, lol), they promised, to overthink, how she will be portrayed in the game. So maybe slightly less shots of her ass and boobs during cut scenes?

Japan: The game is too difficult. Tabata announced, there will be different difficulty settings in the final game, so everyone can enjoy it best.
Also, Tabata announced a patch for Episode Duscae, that will improve the game, like getting rid of bugs (no exploring outside the boundaries anymore), improving targeting, camera and frame rate, adding some new fighting mechanics (roll dodging, weapon use, team attacks) and even new quests for the characters. The patch will be released between mid May till end of May. When the patch has been released, Square Enix plans another Active Time Report.
Final Fantasy XV will not be on E3, but there might be a new trailer. FFXV will be back on Gamescom in Germany though, with exiting news.