You know what sort of OGCDs -do- change things up?
Quick Reload. Do you hit it the moment it comes up, or do you wait to run your other ammo out so you can force another clean shot? The RNG nature of Machinist shots makes Quick Reload a minor but important decision in its use. Forcing another clean shot outweighs 25 potency, but only if done in a certain time frame.
Leylines. Commit, baby. 2000 IQ plays. See the future. Everything about getting a full Leylines off when you had no right to -feels fantastic-.
I hate Summoner, but respect where it's due. Trance feels fantastic, but that might be the Jelly Legs Black Mage speaking.
Any gap closer. Mobility feels good. Hitting things feels good. Hitting things while mobile feels -great-. Distance control is something I hope we see more of, and the Paladin not having an ally target variant will forever be a sore point for me.
And just for the counter intuitive one as well: Bard's fantastic because of one subtle aspect. It puts you into the beat, the songs it sings. How? Every time your poison procs you instinctively know the server tick timing. I can't tell you how badly I want that on Black Mage, but it's easy to lose, and who even watches DoTs, right? Bard's entirety is built around internal melody, and even though it's just a giant walking example of "Spam this !@#%ing OGCD", that one aspect alone is enough for it to get a pass. As stated: Respect where it's due. The OGCDs are directly related to that internal tune.
These are the types of abilities I want. Stuff that actively changes your approach, in that one moment.