^^^
Mega-ethers recover 20% of your MP (Max of 600), Hi-ethers recover 30% with a max of 300, not sure how much MP PLD has so Hi might be better than Mega if their MP is lower than 900ish. Mega restricts medicines for 5 minutes, Hi-ethers for 4:30. Not bad in a pinch, especially if you can use Megas.

If you have alchemist or know someone that can make the ethers for you, the materials for Mega-ethers are relatively easy to get, the hardest ingredient being Black Truffles which are uncommon from Harvesting and rare from killing Boars.