Why don't people like to pick/use Tenacity over Determination?

[Warskull]

I was wondering if I should do a tenacity meld for Ruby EX. Seems like it might be helpful for the ad tank buster and for the meteor.

Tenacity shines with the adds' tankbuster in phase 2, particularly during progression. That tankbuster hits extremely hard and a missed cooldown or a healer having you not quite topped off can easily result in your death. Some tenacity really helps smooth out mistakes here. There is a ton of incoming damage and mistakes by the DPS will have your healers struggling to keep up. Eventually you get to the point where you don't need it anymore, but it helps on the road to learning the fight.

With the meteor it doesn't help so much and your healers clean that up with AoE. Proper stacking is necessary here.

[Acesfool]

Tenacity shines with the adds' tankbuster in phase 2, particularly during progression. That tankbuster hits extremely hard and a missed cooldown or a healer having you not quite topped off can easily result in your death. Some tenacity really helps smooth out mistakes here. There is a ton of incoming damage and mistakes by the DPS will have your healers struggling to keep up. Eventually you get to the point where you don't need it anymore, but it helps on the road to learning the fight.

With the meteor it doesn't help so much and your healers clean that up with AoE. Proper stacking is necessary here.

Yeah, when I said meteors I meant to say comets. It sucks that you can't use any abilities while "holding" the comet because if you pop invuln too early it doesn't do much good and if you wait too long you can't use it at all. I have enough materia that I can redo my gear several times over so I think I'll give tenacity a try. Thanks for the info.

[Warskull]

Yeah, when I said meteors I meant to say comets. It sucks that you can't use any abilities while "holding" the comet because if you pop invuln too early it doesn't do much good and if you wait too long you can't use it at all. I have enough materia that I can redo my gear several times over so I think I'll give tenacity a try. Thanks for the info.

For the comets do not stand in the final spot. Stand by it near the boss. Once it hits the final spot it glows, you actually have about 2 seconds to pick it up. So you don't have to worry about timing it. You see the final spot, pop hallowed then rampart, then step in it. You get almost 10s of invuln then an addition 10 seconds of 20% damage reduction.

Plus this lets your team focus all DPS on the other tanks comet at the start, that makes the phase go quite smooth. Tenacity probably helps a bit for the other tanks, but as a PLD there is no better place to use hallowed in the 2nd half of the fight.