Quicken

It basically allows someone to take there turn next

Haste typically lasts more than one round, and equates to 42% of agility, so imagining you have 100 agility (a lot, but possible) it would be 4.2 CT every cycle for 3 rounds. I think this works out to about 93 ct. Quicken gives you 100 CT immediately, unit will act at end of next cycle and retain any excess CT. I'm glad this prompted me to calculate this out, I might turn haste off

how do you turn haste off?

go to units > ability set > select ability > select on or off. Characters use highest cost of AP or TP abilities always first. only thing you can do is guess the order of how much AP you will have next because it will always take the max cost it can.