Well if you transferring from PSP2 to PSP2i, you may have to play from the start if you want to play as Deuman race since they're new in infinity.
Also a lot of things have changed aside from it's additional weapons, technics, clothes and hairstyles (some of them are reference to concept art and PSO/PSO2 i think).
For instance, if you thought you've upgraded your weapon to max using extend code, there's an extend code oo that enable you to maxed out your weapon even further.
Then, there's a rebirth point that used to increase your stats but your level will back to lvl1 per each use.