Reading is a good thing. It took a few seconds to find this.
Developer’s Note: With Echoing Nightmares transitioning from a Seasonal theme to a permanent feature moving forward, we felt it was necessary to dial back the Experience rewards to avoid players feeling obligated to maximize their time spent inside the activity. Our vision for Echoing Nightmares is to be a fun bonus activity, like the Vault, that serves as a good source of loot and Augment materials. We’ve also made several changes to Adventure mode and difficulty unlocks—these will align the Diablo III experience across all platforms for new players and should make it easier to jump into your preferred activity. Lastly, we improved the Uber Boss flow so that players and groups can kill multiple rounds of bosses without having to remake games.