The biggest problem with the suggestion to add unique gear effects, FFXI-style, is that it's incompatible with the current vertical gear progression. Make the effect too powerful and people will use the lower ilv gear for far longer than it was intended. Make it too weak and people will ignore it (see current elemental resistance gear). I think there's a cool solution to this problem and it can be found right within the FF series.
In FFIX, certain gear would have unique abilities and effects on them which would become active if you equipped them, but would be lost if you removed that piece of equipment. However, if you gained enough AP from fighting monsters, you could permanently learn that effect and equip it anytime using magic stones, which function roughly the same as cross-class ability slots in FFXIV.
I think a similar system would be very beneficial to FFXIV. Perhaps in conjunction with the first expansion and AF2 gear, if you spiritbonded certain rare equipment like AF2 or Raid gear to 100%, you could keep its unique effects. Effects could include some of the things featured on the old 1.0 AF gear like reduced Presence of Mind recast, enhanced Paeon, store TP, increased Jump damage, etc. Limit it to a certain number of equipped effects for balance.
Bring back unique gear effects but modernize them! No need for gear switching macros, just learn them permanently and expand the range of character customization at the same time!