I believe WG got a boost when they fixed the breakpoint. My WG heals for some 20% more than its tooltip. That plus the 5% rejuv nerf, and SotF is now stronger than it used to be. There's more and more high ranked logs with WG as the dominant heal.
This is me in LFR - no ring/trinket procs, no WG/Rejuv ticks while hero is up, with Treants, DoC and Germination, 20% Haste and 24% Mastery with raid buffs, but I forgot to stop casting well in time before the kill, and let Harmony slip a moment:
Wild Growth:
Raw healing: 6.94m
Total mana cost: 26*12080=314k
Healing per mana: 22.1k
Rejuvenation (18s):
Raw healing: 4.41m+488k=4.90m
Total mana cost: 93*3024=281k
Healing per mana: 17.4k
That's a 27% HPM advantage to Wild Growth, over Germinated Rejuvenation!
My Swiftmends heals for 33k, with 26*4160 added to the WGs mana cost above, and 26*33k added to its healing plus the 50% bonus, SotF-ed WGs gives me 26.7 HPM.
If using Rampant Growth, and casting a fresh Rejuv with 0% healing to feed the WG bonus: Adding 3024*26 to the cost, the hpm becomes 22.5. Even without Glyph of Wild Growth it beats 18-sec rejuv in HPM (22.5*5/6=18.5)
Holy crap. Guys, we need to cast more Wild Growths. Unless your WGs overheal 25% or more than your rejuvs, you should gain HPM/HPS by casting more WGs and less rejuvs.
Incarnation is still a very strong cooldown - just remember to cast WG on cooldown when it's up.