Please take a look at LOTRO for the proper way to design end game dungeons

[Adler]

This is false on so many levels. Gear in this game is vertical, which means there is a best set of gear, period. FFXI had multiple sets of gears for different fights. There is only so far "skill" can get you in the game. There is a ceiling on most end game fights that requires a certain ilvl to pass, you can have the best rotation in the world, it won't matter if your DPS isn't up to speed.

The only difficulty cap in end game content is braindead people. Skill or let's say ability to think is more important than gear.