An excellent game. It's got a cast of great characters and the story itself is very enjoyable. The new engine looks amazing and feels great to play on a controller. Combat is epic and brutal, although it's not nearly as over-the-top as the previous games. EVERYTHING is voiced. Yes, even side quests! There's a few small callbacks to 0 throughout the game which is a nice touch.
There's a few downsides such as iconic characters from previous games being absent for almost the entire game (Majima, Saejima, Daigo). Some of the villains aren't very exciting; some are great. I feel as though the plot could have been done with characters we already know and love instead of a whole new group of people.
Overall a great experience. I spent over 40 hours on it, and A LOT of that was doing fun side activities.