Well after testing a bit on the PTR... Zen Sphere is pretty good for Brewmasters, but I think it still needs a small buff. Right now it heals for about half as much as a Chi Wave, but spread over 16 seconds... I was getting ticks for about 9k and detonate for 25k, compared to Chi Waves 32k per tick.
This was all tested on Target Dummies, so maybe it scales really well, but it will need to scale REALLY well to outheal Chi Wave. Of course the good thing about ZS is it's reliable and has 100% uptime, whereas Chi Wave is still stupidly unreliable. Case in point I had to go out to the middle of nowhere and use a low hitting mob and a /cancelaura Vengeance macro to test Chi Wave as when I was at the target dummies the fucker REFUSED to jump to me.... also it can only be used once every 15seconds.
Personally I'll be taking Zen Sphere, it's slightly less healing, but it's 100% guarenteed to be on you, not jump off to a random dps who stood in the fire.
p.s. Healing Elixirs is epic, gotta love 60k heals for free and that's with 0 health buffs, in raids it'll be even higher, not to mention Fort Brew