I've always been a PLD main here since ARR and I've just came back to game after 3yrs and I have to say PLD has improved, since you weren't around at HW you learn Clemency which is op af and allows PLD to cure itself for huge amounts, you can also now use Holy Spirit for magic dmg but tbh I think PLD should have more divine/white magic spells as it always seems odd that you only have 3, hopefully next expansion

Total Eclipse makes the Job alot more fun now too as you can AoE big groups of mobs and you also get a nice animation skill called Passage of Arms which gives you 100% block-rate while reducing the dmg taken of everybody behind you by 85%.
Things to also note are that because the cross-class skill system has been removed PLD no longer can use Foresight, Bloodbath, Fracture Mercy Stroke, Cure, Stoneskin, Protect, Raise.
They have introduced a new Tank Role set of 10 skills which all tanks get but to me PLD lost out due to making the Rampart skill which was exclusive to GLA/PLD to all tanks now :/
The only thing I'm not really keen on is when I hear players saying that PLD is being made to be the go to OT now due to it's new support skills, as to me PLD always felt like it should be the MT due to having a shield and better dmg migration abilities, I'm not really sure how I feel about it as I haven't really done any of harder content yet in SB but it just feels odd-.-