Oh, I don't know. I'm no expert even after a year of using Spine, but that's the way I've found out to be nice enough. :p
My issue with just using two bone IKs, for walking or running cycles, was that even if I could tell the target bone to be at ground level while in the "contact" stage, I couldn't simulate a realistic arch in the "up" stage.
I guess those problems will disappear when we got separate vertical and horizontal keys for Translation. 😉