It's an amazing game, but probably better for newcomers to the series or people who never owned a PS4. Almost all of the songs were available in the PS4 title "Future Tone", and a good portion of that has been used in almost every Project Diva game released. The "Miku Room" feature is gone, no fan-art during loading screens and no story like in "Project DIVA X". There's a lot of costumes and accessories to unlock with the points you earn by playing songs, but you can't easily choose the recommended costume for the song by just pressing a button. You have to manually enter the menu and select the costume. Also, no english subtitles for the songs.
I still enjoyed it a lot and you'll easily get 15+ hours of gameplay just by playing through each song once. If you're a hardcore fan, go for it! If you're a casual fan and already played Future Tone, skip it.