First of all, thank you OP for making this thread.
I had a few concerns about the level booster items. I'll list them below
*Using a level booster, you'll be leveling a class to 60, not even KNOWING how to use your class
*Now not knowing you're class, you can hop into dungeons / trials / raids, again without knowing your class
*Bragging rights. P***ing off every other Final Fantasy player who worked day and night leveling their characters. That's a huge "f*** you" to our face from Square Enix.