Sound advice, thank you. You're right that ideally I should take small steps and change only one/few variables at a time to properly determine my optimal n.gut/poly hybrid. What makes me hesitate a little is the high cost associated with slow and rigorous experimentation. As much as I love the n.gut/poly set-up, I am inclined to just give it one more shot before switching back to cheaper poly/s.gut.
Still, I think I will follow your good advice and only change (1) and (2) in my second and final (for now) attempt at n.gut/poly hybrid. I may leave Co-focus and higher n.gut tensions for future investigations when I'm a bit richer.
Wilson Pro Staff 6.0 85.