At some point I went from pretty much ignoring this spell line to loving it. Especially since it's affected by extended buffs, I can get an Eye cruising around for the better part of two minutes and there's a lot you can safely check out in that span.
However, I've noticed some places have "dead spots" that kill the eye. Most recently I noticed that when you get close to Tawro or Radir in Umbral Plains your eye will just "drop out" -- the buff will immediately end. If you're near the spot, you can see your eye spin for a few second before it goes away. Does anyone know if these spots are intentional or just glitches in the system? Seems strange that they'd work to "hide" these mobs (who can be tracked anyway) but I can send my eye all over Akheva Ruins and spy on all the real raid mobs.