I'd guess one of the bigger differences between MT and OT would be their boss positioning/kiting ability. PLD excels in it from the sheer amount of ranged GCDs the job's got, I'd imagine the new Tank has similar. A long GCD could also be used to a similar effect.

Also maybe one of the two long defensive cooldowns PLD has may be exclusive to the job while OT gets an extra group mit or dps button