Arguments, arguments everywhere. Sigh.
Ok, sighs aside.

What about SCALING UP the content based on the party's overall gears instead of what OP has mentioned?
I don't know how true it is, but someone told me that the Limit Break is based on the current party's gears and not the one who uses it.
Likewise, I think SE can really work on scaling up the dungeons' difficulties so that people with ilvl90 gears would clear the dungeon as fast as people with lower ilvl gears would.
Cheers.