What is the significance of gladiator's armor?

I see lots of farming threads for warriors stating gladiators armor as a requirment... I don't understand why. Aren't all armors the same?

thnx

Before the insignia system applied to tyrian armor, gladiator armor was the set that granted extra energy.

They're simply outdated.

Gladiator armor is equal to radiant insignias btw

Gladiators used to be all stuck with Radiant Insignas (+Energy). However, now, you just craft the armor, and you can personally choose which runes/insignas to put on it.