Update-
I got the spiral cutterhead from Byrd about a week ago. Turnaround was a little shorter than quoted at about 7 weeks. Install was simple and only took about 20 minutes. The tolerances were dead on, so hats off to Byrd tool. First impressions are that its quiet, leaves no tear-out. Finish was better than I was expecting. Won't burn. Tested only on white oak w/ 20% MC so far. Let me know if anyone has any specific questions.
Trevor