So far we know little about all of the changes that have been made in the new releases of the game. However, as it currently stands, a few big differences are obvious.
1. The duplication glitch.
2. Frame rate and load times.
3. The text effect glitches are still intact. Familiar retreat glitch, jump menu buffering, levitate skipping, and gateway skipping are all still viable afaik. This is significant.
So far, in my opinion at first glance, the PS3 remains king for the fastest way to beat Ni No Kuni. The duplication glitch makes the run significantly faster due to large amounts of disposable money and restoratives. This gives us the ability to craft chocolates for Royal Jelly, buy upgraded weapons and armor for familiars to speed up fights, and obviously removes the RNG time loss risk of the casino.
I am currently in the process of refining a casino centric route for the remastered versions of the game. Even if a solid route is put together I have a very hard time seeing the new versions being faster than the PS3. Even with load time improvement the loss of our center point glitch is very impactful.
Current consoles from fastest to slowest are : PS3, PC, PS4, Switch.
I will make changes if anything comes up.