Leveling was the same as in any other final fantasy, you gain exp you level up.
I think you refer to the junction system, but are you implying they should change the most unique thing about this game? No, thank you.
When they first announced it I was a bit skeptical, but now that I look at the screenshots im pretty pleased with how it looks. Feels a bit weird buying this game for the 6th time, but what can a ps1 FF addict do? 🙁