I’m planning to get the “Ultimate Edition” from PSN that includes all the DLC. However, will the save file for my retail copy work on this version?
I went ahead, bought the game, and sadly the save files aren't compatible. The save file of the retail version is named:
Persona 4 ARENA
While the PSN version is called
Persona 4 ARENA [DL]
Why this is the case is beyond me. The fact that I won't be able to use my old save file is very depressing.