While I'm no career/veteran PLD, I love PLD in Campaign. I used to use /DNC for a while and it was the main choice for most. It's kinda a drag after a while, though, just throwing up waltz after waltz.
But, after leveling SCH for SMN, I now /always/ use /SCH for campaign, and just thought I'd put my thoughts here for other PLDs to see and ponder over. Keep in mind that everything is just for campaign and solo'ing some tougher stuff, nothing other than that.
Gains from /SCH:
-Sublimation; A max charge can give me well into 300-400MP, It's an extra 2mp/tic.
-Light Arts; Shaves 10% off your MP cost, cast, and recast time on cures.
-Dark Arts: Viable Drain and Aspirs, it's surprising how many mobs in Campaign actually have MP, even non-mages. You can usually pull off 100-200 Drains and 60-100 Aspirs.
-Addendum: White; Reraise, -na's
-Addendum: Black; Sleep and Dispel if needed for their usual benefits or extra hate grabbing if you're being contested for hate on a mob you're tanking.
-Stratagems:
Penury and Parsimony, reduce base MP cost by 50%, good for those big cures while conserving MP.
Celerity and Alacrity, Halve reprisal recast (love this, it lasts 1min and leaves you with 30s downtime, so most of the time, your casting is virtually unhindered, even when being beat on by multiple mobs), flash timer, or Drain or Aspir, or Sleep
Other bonuses:
Regen II etc
I could just be stupid, but I really like the fun I have with /SCH so I thought I'd share^^ /SCH has allowed me, (where I wouldn't have been able to before) to take on multiple mobs in campaign at once, solo stuff like Orcish Overlord, duo Aqrabuamelu, and solo a variety, (but not all) EM-T's with ease.
If you'd like your time back after reading this, complaints on a postcard, please. ;p