We have a bag of GHK Nene instant open right now, we have not yet tried it in medium grind. Like the frozen fresh from Pu'u O Hoku ranch, I find it has a clean and slightly nutty flavor (pine nut/pinion).
for me, Nene fresh and instant have been nicely balanced in effect loaning to a calm state of mind and loss of tension in the neck and shoulders but no couch lock. I wouldnt call it strong, but it lets you know its present and working.
glad you asked this, i see GHK has some Nene medium grind in stock, first time in the year I've been closely watching their inventory as they quickly rose to top vendor spot for us based on flavor and effect of Chris's excellent Awa's offered. just put in order for few pounds thanks!
we really like the Mahakea, both medium grind and instant. as I've seen another report in forums it tends to be balanced at first and gets heavier the more shells drunk for me, supports a good head space, and is a great late afternoon into evening drinker.
You got two good ones, imo, you'll likely enjoy alot!