But don't you think that past i90 for Allagan and Tome sets that they could at least expend some effort to make everything have a unique model? I don't think that's too much to ask considering it's end game gear.

At least for the Allagan gear there's -some- justification considering it prevents unnecessary expansion of the loot table to accommodate all jobs (For instance if you make Summoner/Black Mage Allagan into two different sets then that makes it that much harder for that job to get their drop), but there's no reason things like the Bard/Dragoon sets in CT or the Caster/Healer (or Dragoon/Monk/Bard) sets in First Coil should all have the exact same models.