I just bought a Z28, draw weight is 70-72lb, shooting 100gr rage and my draw is 29", from my nock valley to where arrow sits on rest is 26.5" so I would go with an arrow around 28"? Easton and Beman calculator put me in a .340 spine. I was looking at the Beman MFX classic or Easton Axis N-Fused. I like the MFX weight for kinetic energy. Would I be better suited with a .300 spine and a little longer arrow? I hear the Z28 radical cam can be tricky to dial in. Thoughts??