Nothing I've ridden is worse than flows. (As mentioned in the OP) - not going that route, not asking about flows. Not interested in flow, not to sound ungrateful- thanks.
What specifically intrigues me about the gnu in particular is the 2 straps, 4 solid contact points, like a traditional binding, but addition of rear entry. That, in theory, would fix much of what keeps flows from riding like a traditional binding... and enhance the rear entry aspect to boot (no pun intended).
I thought the K2 was a close sibling, but I'm concerned the K2 might also (like the flows) potentially lose a feeling of solidity, with the actuated frame [and potential movement] that the gnu doesn't have.
If not the gnu, I'm sticking with one of my traditional favorites, Burton Missions, for my Pickle. That's the reference standard, for comparison.