I would like to see a kind of difficulty of XI on ARR. Now before anti xi'ers or fanboys jump this let me explain.
XIV difficulty was trying to avoid laggy cracks that basically split players between "F-you noob lolyoucantavoidcracks" and "F-youit'snotmyfaultSEmakeslaggygames", or trying to beat a dungeon as stupidly quick as possible only to not see DL untill 20 speed runs later.

In XI a good example of difficult im looking for would be Salvage. To even Salvage you had to beat story quests to a certain point, then beat out all the assaults with a full pt who also beat all assaults, then assault more to make points to even go into Salvage. After all that work youd get thrown into a dungeon completely naked, with no weapons, no ability's, no magic NOTHING and it was your job to unlock those ability's before you could go fight the monsters that dropped great gear. EVEN AFTER ALL THAT the drop wasn't 100% you hope to unlock enough ability's for your pt to succeed went to fight a big baddy and -maybe- got 1/3 of a armour peice that you wanted.

After all that you'd keep assaulting for points, then salvaging to try to get 3/3 on a armor piece, collect items to have it made to a salvage armor then turn it in to a NPC to have the peice you wanted.

THAT was work and people running around with salvage gear were regarded highly.

Salvage difficulty is the kind of timesink hard work and dedication that I loved of XI and much less annoying(imo) then standing around CC' failing 5 times waiting 15 mins to reenter, looking for a new tank that D/c half through the battle and going to bed that night without a single speed run complete. Or having 10 speed runs and no DL.