I'll tell you why this is a GREAT question.

I switched from Radial X-weaves and a/c/c 3-49's to a/c/c 3-71's last year. I was trying to get a heavier hunting arrow setup. What I didn't take into account.....was the difference in arrow diameter with the switch. The 3-71's are a larger diameter arrow. This threw my sight off a LITTLE. What it also did was bring fletch contact into the equation. What used to go by my cable on my Bowtech would NOT go by now, because the larger diameter arrow pushed the vane into the cable, causing contact.

Something to ponder. I had to switch the orientationof the cock vane on my setup to thwart this.

For normal hunting situations (shots to 40yds) I saw NO discernable differences in POI, though, with the heavier spined arrows. I was also pushing them down range at likely 300fps, though.

Just an FYI.