Paladin's only real issue right now, is it's subject to the hate cap, just like everything else. For Paladin to really come back, it needs a way to circumvent the standard enmity cap, and allow Damage Dealers to attack with impunity.
An Ochain PLD is literally, unkillable (Save for Death and Doom Effects), but at the moment, that will just make PLD the last one standing, not make the alliance/party safer.
If you Love PLD as a Job, yes Ochain is worth it, especially how it allows PLD to Lowman with little more than a Bard, simply to speed up the kill process. If you're an elitist all about just getting the best, then, well, no. Ochain isn't worth the time, but the game is much more satisfying if you play it how you enjoy it, and not how others tell you to.