I havent been at any given boss fight after Bloodboil but any of them must be made to be doable with 9-10 healers in raid. That is only true if you think the instance must have good overall design. If you need 6-7 healers for whole instance and 9-10 for one boss than you have a problem.
Yes i know we are talking here for top guilds only atm, but what will happend when average raid guild come to this point? Not everyone have the luxury of 10 people waiting in front of the BT.

The point is that you can do whole ssc/tk with the same raid and i dont think this is the case with BT at the moment.

Well doesn't it arguably only "require" 9 healers because you're still gearing up? Wouldn't increased healer longevity, increased HPS via +heal and especially +haste for the burst healing, allow for a reduction of that number?

When we first killed Patchwerk, we brought 17 or 18 healers, which was more than we'd bring for any other fight and more than we'd bring for any DPS check in the zone, but that's because we were undergeared for the fight. Later on we could do Patchwerk with 14 healers no problem. Isn't that how it should be?

So gear replaces skill and execution? Healers are readily replaced by epics? I don't think thats a very good design personally. We beat patchwerk the same way week 1 as we did week 30 or whatever it was, same class makeup, same theorycrafting quotas - maybe he died a bit sooner. The whole idea that you have to outgear an instance to stand a shot at it is well - not good imo. Its a massive step back to the everquest days, and should have been moved past. So we use 18 healers to get us epics, and now we bench them down the road once they've served their purpose.

Gear should serve a purpose to make things easier - to some degree. The best guilds should be able to drop illidan with execution, while gear over time allows others to catch up - as it was before BC really.

Once you beat an encounter - over time execution and strategy and gear makes it slightly easier - but that isn't the encounter 4 months later. The time that matters most is when you first beat it, and what strategies are in play to do that. Every major end-game guild stacks their raid to no end really, if that meant 15 healers, or 15 tanks to get a world first - you can bet it would happen.

You could argue that 4H required 8 tanks. But then we could also say it was doable with 7, or 6, or now adays maybe 3-4 tanks. But realistically, it required 8 for every first kill. Some guilds brought 10, some brought 7, but it really was basically "8."

Well, I'm not sure that 9 healers really counts as "stacking." If the fight required 12, I'd be bitching. You have 4 classes that can heal. So let's say you have 3 paladins, 2 holy priests, 2 resto druids, and 2 resto shamans on a raid. Is that a "stacked" raid? Back in 40-man days, 15-16 healers was typical. 16/40 = 40%. 40% of 25 is 10. And back then only 3 of 8 classes could heal, now we have 4 of 9 that can.

I'd agree that an encounter that required serious stacking of one class until you were overgeared for it would be bad, but I differ regarding the definition of serious stacking. We typically run with 6 healers, and have done every fight through SSC/TK and the first parts of BT/Hyjal with 6 healers (Naj'entus with 6 healers sucked fyi). Obviously we'll need to bring more for this. But 6 is very healer-light. I'd say you have a spectrum ranging from 6-10 in terms of a "normal" number of healers. Below 6 and you're insanely DPS-heavy. Above 10 and you're stacking healers.

If the complaint is that a healing intensive fight is much easier with a healing-heavy raid, I'm not sure I see the problem with that. This isn't raid-stacking, Naxx style, where 4H means 8 warriors from now until eternity, or where any hunter or warlock you bring to Loatheb is always going to be a complete liability. Bringing an extra rogue or warlock for a DPS burn fight, or an extra priest or two for a heal-heavy fight, doesn't really strike me as unreasonable. They may not be "necessary," but of course they're going to help.

And, of course, DPS gear progression is even clearer than healer progression, so the fights that people think might not be doable with 8-9 healers right now will be doable as people continue to improve their DPS gear.

Yes i am aware about gearing but if you want to do the fight with 7 instead of 9 healers than every healer need to have 30% more hps (i realy dont think mana can be issue with shadow priests). With full t6 gear maybe i will have that hps but this will require a lot of time and untill then we are stuck with people for one fight only.
Patchwerk is good example but cant cover the "mage" problem of Bloodboil. At Patchwerk we had healers with better gear but we had tanks with better gear too. Here we have "tanks" with same gear as on out first kill. Do you think you would kill Patchwerk with 14 healers after few months farm of Naxx if your tanks had only pre Patchwerk gear?

I agree that gear is supposed to help people beat encounters, I am just saying that basically what is "required" is really what you see your first time there, everything after that is just farming. If this requires 9-10 healers, thats what it is for today really... that was my point, cause even on patchwerk, one should be able to use the same strat on day 1 as they do months later without it feeling like you're gimping yourself.

People will do anything necessary for a kill - even if that means, for instance, stacking. Yeah, this isn't really a bad example of stacking - and I personally don't have a huge issue with stacking within reason.

Essentially encounters shouldn't require 6 months in SSC and TK25 to beat in BT - and likewise, gear shouldn't be able to cut your healers by 25% - both of those seem like bad designs. I know the reality of the situation doesn't match the healer point. But its like you said with Hyjal and doing it with 20 or so people instead of 25. On vashj and kael for instance there are enough moving parts that people won't be readily replaced by some purples later on.

You need eight healers and two Shadow priests to even have a shot, I think. Each of your healers has to output 1500-2000 hp/s for the entire fight, potentially with spikes much higher than that. You can talk all you want about gear and progression and strategy modification, but the fact of the matter is, the damage being thrown is just too great to be remedied by any method other than stacking healers. On one of our earlier attempts, we had a priest overtake the main tank thirty seconds into the fight. A Holy priest. Bad precedent.

While I can't speak from experience, from a pure theorycraft perspective a single tree druid should be able to heal through 4 bloodboil victims by stacking lifebloom on them, and if you toss them a shadow priest and a stack of super mana potions, mana would most likely be a non issue. Get 2 trees and they would be able to heal through bloodboils while stacking their HoTs on the tank as well. Restoration druids excel at efficiently healing through predictable damage, this seems like "their fight" in BT.

Whats the enrage timer at the moment ?! Bringing it down too far would make a threat sensitive fight a nightmare :/
I do think gear will help, its not going to stop prayer of healing being one of the most powerful tools for the encounter though.

We didn't get to see it pre buff, but the debuff change from 1 per 3 seconds for 18 seconds to 1 every second for 24 seconds is insane, this to me is tweaking with a sledgehammer.

My biggest grumble with it, is watching our lower hp classes die to the 5k per second dot after the hp buff from fel rage has worn off. That is just broken.