Osse said:It's very true that you need to swap appropriate gear for maximum potency. This applies to every job, not just BLM.
But the AF2 pants example is making a moutain out of a molehill. The AF2 has +13 MP and +3 Int and a bonus for the element of the day. The Errant Slops have +7 Int, the main stat a BLM is interested in, unless he's doing slow and paralyze for some reason. (Let's not bring the +1 version into it, since it's only marginally better for a whole hell of alot more gil).
Four more Int will equal between +2-3% damage, and on a non-bursted Thunder 4 thats about 20-30 damage, perhaps as much as 40 damage.
Now, the reality of the situation in end game is that you want effeciency. You are fighting HNM's and need to make your MP count, so you cast the most effective spell you can for the mob. Or, you are trying to chain mobs as fast and as *long* as you can in an xp party. If you are wise, you choice of spells will be based upon the mobs' weakness, THE DAY OF THE WEEK, and any prevaling elemental effects. Not to mention, most of the SC's you see will be either Light or Darkness, so there is a 50/50 chance that you can MB a spell appropriate for the day of the week. Although the BLM nukes do more damage as you go up in spell level, the damage:MP ratio is about the same. The only way to improve effeciency is to cast a spell consistent with the day of the week, and there is a 50% chance that you can MB it as a bonus. So the pants are more useful than you let on, assuming you actually take advantage of them. But they are not good for everything, that is true.
Or, as another BLM scarcasticly told me once: "Didn't you know, when you hit lv 75, every mob is weak to Thunder 4." And you can just nuke away to your heart's content.
Ok let's see-
There are a few factors you're forgetting that lead us towards the path of Blizzard and Thunder 4 only as far as nuking is concerned.
1. You mention MB: You want to MB your strongest nukes as long as we're talking about dmg/mp ratio.
2. As you reach your final nukes, your dmg/mp ratio increases. From 65+ the base dmg off the single target nukes increase much more rapidly than the previous 65 levels, the DMG/MP ratio in fact increases as a result, making those last 2 more efficient.
3. Blizzard 4, built in 10 elemental magic, built in 5 int bonus, nuff said.
4. Spike dmg > clear mind resting. More damage over the course of several fights.
5. Merits - thunder and blizzard potency. You'd have to be on crack to put it anywhere else. Those merits alone > AF2 legs bonus.
6. Ignoring 1-5, matching your nukes with the day of the week may SEEM more mp efficient, but they aren't as time efficient - and to a mage with the ability to hit a rest macro, Time = MP.
And by the way, you mention day of the week as a huge factor in your endgame spell choices. Have fun fighting Kirin on earthsday.