Let me try to address a few of the concerns raised in the thread and explain our thinking.
First off, why this wacky raidwide effect? Why not a traditional legendary that is purely individual? The idea's origins lie in what this particular legendary is: a ring. It's not a weapon designed to strike foes, or a shield to protect you from harm. And what is the nature of a ring? Whether we're talking about seven rings for the Dwarf-lords in their halls of stone, about Captain Planet, or about common social covenants in our own societies, rings tend to be paired with counterparts, and to have their meaning derived from the connections entailed therein. A lot of fluff, perhaps, but that's what got us thinking along the lines of a group effect rather than a personal one. This certainly isn't a template for all future legendaries, but we find it very fitting for this particular one.
Now, some of the concerns that have been voiced:1) "It will be used mechanically on cooldown"
Sometimes, sure - it depends on the fight. The healing/tank versions certainly won't be used that way, and the DPS ring also has elements (notably the AoE explosion at the end) that add additional depth to the decision of when to activate it. Let's consider the fights in Foundry, since those are probably more familiar examples than Hellfire, and imagine how the ring might have been put to best use while progressing on a few of those encounters:
- Blast Furnace : Largely wasted if you use it on the pull; you might save the first activation for the second pair of Operators, and then during the second phase you'd aim for windows of Elementalist vulnerability, since that's what matters most.
- Operator Thogar : Here we run into some unique considerations associated with the explosion. You could activate the ring in advance of a Man-at-Arms wave, getting a damage burn on Thogar while you build up the potential AoE that will go off just in time to alpha-strike the dangerous enemies right as they jump off a train car.
- Flamebender : If you aren't running into her berserk, the Cinder Wolves are your main concern. You'd probably benefit from waiting until she's at 45 or so Energy, and timing the explosion to get a large head start on the Wolves. Especially on Mythic.
- Blackhand : Aside from the obvious uses to speed up phase 1 and phase 3, I could see having your initiating player as the person who's about to get knocked up onto a balcony with a fresh wave spawn due, timing the explosion to pretty much erase the whole wave of enemies right as they exit the door on the ledge.
Now, on something like Gruul, you probably would just use it on cooldown every time. But I'd say Gruul is more the exception than the norm. 2) "It feels bad to have someone else control my legendary"
This is a fair point, and I sympathize. Setting aside the fact that when doing any solo content you have complete control over the activation, there is still more control with this legendary than with nearly any of our prior examples. Procs could occur at completely inopportune times, often wasting them entirely, and whether you got lucky and had Xuen's cloak trigger just as a large pack of enemies got clumped together, or whether it fired 10 seconds earlier or later, could drastically alter your total damage on a given encounter.
At its core, the legendary ring is a raid item - the vast majority of the content and the collection steps take you through raid content - and players who are part of a raid group are by definition cooperating and coordinating to tackle challenges. The rings add another layer to that teamwork. Even outside structured guild raiding, it's neither typical nor tolerated in pickup groups for, say, a mage to use Time Warp to maximize personal damage at the expense of the raid, and I'd be surprised if it's common to see it done with the ring. Now, yes, in Raid Finder, though you also won't generally be seeing raids with tons of ring-wearers, you'll probably see some selfish behavior. But even then, the effect isn't wasted (merely suboptimal), and that action isn't likely to affect the group's success or failure on the encounter as a whole given Raid Finder's tuning.3) "The effect isn't fair/balanced and is worse for my spec than other specs"
True. We could have made a perfectly evenhanded ring effect - something like "Equip: Increases damage and healing done by 10%." That also would have been very lackluster. Nearly any effect with any depth to it will benefit some more than others so long as our classes/specs have varied strengths and weaknesses. (And we don't feel that class homogenization is the answer, either.) Over the course of a fight, that may amount to a difference of a couple percent damage, if that. Hopefully we continue to make interesting and unusual items, and some of those will favor specs that feel the ring was suboptimal for them.
There's nothing in particular about the ring's design that discourages raids from bringing people who don't yet have it, as compared to any other type of legendary or any player-power increase. Players without the ring will do some percentage less damage (or healing, or have one fewer tank cooldown) over the course of the fight as a whole, but that's just the nature of any big-power item. It's not really different from the cloaks in Mists, or theoretical alternate versions of the ring that had no group synergy component. I'm sure that later in the expansion there will be guilds and pickup groups that strongly or exclusively prefer people with legendary rings, but that's a social dynamic that's nearly unavoidable with any form of player power progression, whether it's a specific legendary or just item level in general.
Also, as a separate clarification, I wasn't saying it that it won't be used on the pull. It absolutely will be used on the pull in the vast majority of cases. However, the cooldown is short enough that many other opportunities will arise to be more tactical with its use as the fight goes on, rather than just using it automatically every 2 minutes thereafter.
Finally, nothing in Hellfire Citadel is being tuned around having the ring. That's a big part of why it is not currently available to use in PTR testing. In Siege of Orgrimmar, many players had their cloaks before they first set foot in the zone on the day of the patch, which somewhat diluted the impact of completing the cloak since those players didn't really get a before-and-after comparison of specific fights once they'd earned it. Cutting edge progress in Hellfire Citadel, on the other hand, will occur without legendary rings in the raid. And then as raid members complete their rings, the power of the legendary will help you overcome Gul'dan's forces.