5th job and buff duration
With the new 5th job announced, buff duration suddenly seems like a very good IA (as opposed to say, attack speed).
First off, the removal of the dmg cap means having a longer infinity is way more beneficial. 50% buff duration means an extra 20 seconds on infinity during which you would be dealing about 2.5x your usual dmg.
We are also getting a new toggle which converts 8% mp per attack into 15% final dmg. 8% mp cost is ALOT, but remember that infinity makes it so skills have no mana cost. All the more reason to have a longer infinity.
Lastly, i assume the new bossing pattern for bishops will be to simply cast pray for as long as they can, and then attack while it's on cooldown. Depending on the level, pray lasts between 41 and 90 seconds, and has a cooldown between 120 and 90 seconds. This duration/cooldown fortunately coincides with infinity's cooldown, so i assume bishops will simply alternate between infinity and pray. Again, all the more reason to have a more powerful infinity with buff duration.