I was on the test server to experiment with the new Monk Special ability.
Fortunately I have a near perfect hp+ build. The only pieces which I think would make it better are Verthandi's Gem, Bloodbead gorget and Plenitas Virga.
http://www.ffxiah.com/item-sets/279169
The doubling effect only doubles base hp and hp+ number effects. It will not double hp gained from +hp% effects like on the melee gear set or mantra. Although the total hp will be greater w/ melee set rather than items like jurfu cloak or torrid gages.
With fully merited Mantra, augmented melee +2 set, and the new special ability on mnk/drk, I was able to get 7104 hp. (w/ the slight improvments listed above, 7428 hp would be possible)
any separate forms of +hp% will calculate as a separate step based of hp +hp gear.
Ofcourse cruor buffs and mantra will occupy the same slot, so they cannot be stacked.
Inside abyssea, I found that player hp is capped at 9999. There are no 15k~20k HP builds.
I took some hits from mobs when my hp should have been much higher than 9999, but hp still went down.
Still you can put together a fund build of 9743 hp using sanguine scythe, razed ruins and ebon hoof atmas.
When putting up the sp2 and souleater, all your melee hits in abyssea will be for ~1000 damage.
if you go vs arcana w/ arcane circle up, crit hits can do 2.5k.
Fortunately on test server there is a 10 second recast to the new sp2, so you can actually survive doing this...
it is hard to maintain a high hit rate in such an hp+ build (no extra double attack, triple attack or haste) but, it melds nicely with 100 fists .
Best damage can be done by the following:
Focus
Impetus
Victory Smite w/ 300% tp aftermath
Swapping to hp build including full melee +2 augmented gear.
Souleater
100 fists (augmented duration)
New Special ability 2
Pray you have lots of mages curing you!!
This would actually give mages something to do after the PD + embrava (you need regen!) go into effect.
If fighting arcana, the circle effect is also a very nice bonus.