This game is amazing. The story is really good, the cast dynamics are the best they have ever been (which is saying something because 7 had amazing cast dynamics already), and the gameplay is a massive improvement over 7's already fun combat. Dondoko Island is also some of the best side content that this series has ever seen, and on Kiryu's side, the Life Links and Memoirs are the best possible use of fanservice.
With all that, it might seem like the perfect game, but while the story is really good, it doesn't have quite the same impact that 6 and 7 had. The villains are also quite weak in this game. I love the theming around Bryce, but he doesn't get enough time in the sun to really hit me hard. I also don't really care about Ebina. They certainly do not reach the heights of Aoki Ryo. I also do not think that Akane has quite the same emotional impact as Aoki Ryo or Arakawa Masumi, but she is a great character in her own right.
Another criticism I have with this game is that the randomised dungeons in Hawaii and Ijincho are quite tedious. They're the main grinding location, but the level 50 tier's exp payout is pitiful (which for main story I guess it's fine, since the final boss is only level 52). That, and the battles themselves aren't as tailored or fun as the Sotenbori Arena in 7.
Again, the game is amazing, and I'm very satisfied with it, but it was not as good as 7.