Sky/Sea please.
I would love to see that system implemented in effective way. Those systems guaranteed that even when group of people got highly pimped, they will still redo them for others who just started doing end game for equipment, since the area is open and still they would be able to join with their gear. Even when they aren't helping they would even farm triggers for Gil, and then the growing LSs can spend LS's bank to buy triggers to speed the gearing up process.
It could implemented in such a way that it won't overlap with anyone progress. such as, killing objectives or completing certain tasks would complete the conditions that would spawn the trigger's monster, then spawning the HNMs with the set of triggers, and then facing the final boss of such area. "YES to Absolute Virtue, maybe?". In that way, you would have plenty of events to work as LS such farming days and looting days.
When you have such a system you would end up with, smaller farming monsters "conditions", smaller NMs "triggers", HNMs "bosses", big boss "final boss". Now, talk about the juicy loots! you can play around with the equipment around this syste, simply search on google images "ffxi nm system" and see the amount of items that can be obtained.
Such areas would be populated with LS who doing their events. Alliance doing fights, parities doing triggers and solo completing personal tasks. These areas would be active 24/7, by new and veteran players. guaranteed.
EDIT "After checking 2.0 road map":
Instances Raids would create a void after certain amount of time, where the players who started doing such instance would move on to a newer instances for better equipment, leaving the "old" raids to rotten in hell for the new players who just started the gearing ladder. True the Content Finder might find people for such a raid, but what about when they move to the next one, you would end with 2 voids of closed areas that older players won't bother redoing since it won't benefit them in any way.