My main points are that since mp5 got buffed after the patch, healing scales much more gracefully, ecpecially in pre-patch fights which were designed to be handled with much lower mp5. And second that healing actually saves some mana, while mp5 does not compensate for lower healing in progress fights which tend to be intense (In non-progress/farming fights you usually dont’t actually have to worry).

After considering his suggestions and reading the post again, it seems that there is one parameter that you have not taken into account.
“Healing more now, reduces the need to heal in the future”

Lets take the Nalorakk fight for example. Not really a burn fight like gruul but quite damage intensive and relatively long (~7mins for us).
It also requires changing healing targets a lot while the phases change, so you have to keep your healing output high.
Lets assume that you are designated to heal only the MT/OT and ignore all others.
Nalorakk hits hard, so you have to stack lifebloom and rejuvenation fast on the tank and do it every time for each phase. However, I found that the tank kept losing HP and had to use regrowth to heal the difference and use the extra HoT to prevent him from leaking too much hp again. And sometimes even an instant HT to prevent it from dying.
I found myself after using a pot and a “spirit sticked” innervation almost oom at about 1min before the fight ended. And I blame regrowth for that.
Having bigger +healing (almost +80 more with the meta and all teardrops), would postpone the need to use the less mana efficient spells. It would also save my friends’ mana because they would not have to heal much to deal with spikes and give us some more time to breath in “Oh DAMN” situations.
So my point is that +healing is actually “Mana saving” while mp5 is “mana regenerating”. I actually tend to prefer the 1st.
And two final points.
Post-2.3, mp5 has taken a great boost (30% of spirit), meaning that you can now invest more in +healing and have the same or even more mp5 efficiency as you would pre-patch, while the fights have remained the same.
And second, there are several efficient technics that can compensate for lower mp5 (trinketing/staffing innervates, innervates from others, use pots when cd is down etc), but none efficient ones for compensating for lower +healing (spamming regrowth?????).

I’m not sure I understand your point about healing output. If I’m running LB x 3 + Rejuv + Regrowth, I don’t have a tremendous amount of time to be casting anything aside from Lifeblooms on raidmates. Aside from a Nature’s Swiftness, I can hardly ever use a Healing Touch (of course, I don’t have the talents to reduce casting time). Regardless, as I said in the post, I found these numbers by running an analysis on an existing fight. To find a more accurate value, I would probably need to run it over several different types of boss fights.

I’m willing to concede that 1 MP5 might be worth slightly less than 11 +Healing. But I haven’t done the extended analysis to determine exactly how much. I just wanted to show the process for determining your own personal value. The rest is really up to you!

And if only we lived in a perfect world where our tank Lifeblooms never expired! Personally, I want a set bonus that makes them last 2 more ticks like the one for Regrowth.

If you ever do any analysis of your own (using this or another method), I would love to see your results.

+healing has a HUGE impact on your Lifebloom ticks, as you have correctly observed. So if you were to trade in your +healing for mp5 at an 11:1 ratio, what you would find is that your lifebloom x3 is ticking for a lot less. To make up for this, you will have to cast more Rejuvs and Regrowths, which are much less mana efficient spells and require more MP5 to sustain. In addition, in mainatining these spells you are much more likely to end up letting your Lifeblooms expire, particularly if you are healing people other than the MT. Allowing LBx3 to expire and then reapplying three stacks is less mana efficient than maintaing LBx3.

Also, there is the matter of your total healing output. Once you have LBx3, Rejuv, and Regrowth stacked, any additional healing requires you to either be out of treeform to cast healing touch or spamming regrowth, both of which are enormously mana inefficient. So assuming, neither of these are a realistic option, the amount of healing support you can put out in a mana efficient manner is very dependent on your +healing.

Do a math calculation that applies generally is impossible, because how you balance these factors will vary from figt to fight. Some fights you have to heal others, some you’re only on the MT. Some fights you need burst healing, others just dropping LBs around the raid will do. Some fights, you’ll need only to put LBx3 on the MT. Others will require you to maintain all three HoTs, and even then keeping the tank up is challenging.

The bottom line though is that +11 healing is worth more than 1 mp5. How much is a harder questions…