The release can make a difference, but not a huge one. I can't see the absolute best release in the world vs. the absolute worst release in the world, shooting the most unforgiving and finicky bow in the world, making that kind of difference. I haven't shot with Jason, but I would be quite comfortable putting money on him having a good release.
"ACC 300s with 100 up front worked ok until about 28 yards when they showed weak."
That statement has really been puzzling me. How does an arrow--aluminum, carbon, wood, aluminum/carbon composite--loose spine downrange a certain distance?