[Iarhen]

I think Meoshi is misinterpreting a quote of LOTR, that says that thanks to Vilya, migthiest of the three, the stars shone brigher above Lord Elrond´s house than in any other place.

Otherwise, Im still doubtful about the status of Vilya as "mightiest of the 3". Gandalf says that without the rising of the dwarf kings on the northern mountains, Angmar or Smaug, or other forces from Sauron coming from the north would have wiped Rivendell out.

And we see a Lothlorien, protected by Nenya, fending off the 3 direct assaults from Dol Guldur. We see a Lorien protected not only from the Fortress of the Black Forest, but from the Moria goblins and from the direct view that the Eye of Sauron had over Lorien (an Eye that had a difficult time seeing Rivendell thanks to the Misty Mountains).

The mightiest realm? Lorien. And you cant use the population numbers (Lorien had the greatest, obviously) because there were a lot of the Noldorin high elves dwelling in Rivendell... elves whose names were worth for a 1000 swords...

My conclusion: Nenya was, at least, more powerful in terms of preservation and in terms of defense. Vilya was second.