I've personally had the Melo Melo and Boroguru from Kava Society, and they're probably the best processed roots I've ever had the opportunity to consume. It makes up a super light grog, with agreeable taste that has the full power you'd usually see out of roots that were much more bitter.
My first kava experience was with Pacific Elixir and it gave me a stimulant like krunk with lots of energy but that also had stomach discomfort and some anxiety from the energy. It also put me in a very conversational mood. The many other times I've used it it was a standard kava experience.
Pacific elixir is awesome but definitely tastes nasty (funky, like nangol noble) and it's not a kava I can chug all night. I can put away maybe 3 shells and then I need to switch to something lighter or I will get too krunk. That being said it is far less offensive to the stomach than most heavy kavas.