Rock,
I have used both a lot and flight characteristics are very similar. It is pretty easy to see that the Grizzlystick are a superior to the AD in every category except cost. The Grizzlystiks are now made by Victory and are precision high quality shaft.
More importantly is finding a spine weight in either brand that is ideal for you. I got stuck between spines with AD, which would seem impossible.
I was all in for the AD Stingers but got frustrated with quality and consistency of spine and straightness so poor that 1-2 per dozen were unusable. Maybe my post will get pulled but I spent a hell of a lot of money on AD shafts, and every time I go all in for hunting season I get an order of poor quality shafts.
So I purchased the Grizzlystiks. I quickly found you don't have to worry about spine from batch to batch and they are much straighter. I was not a fan of the outsert on the GS. But now I like it for its toughness. The GS is a smaller diameter on the front and seems to penetrate deeper in targets. I have used them very very hard and have not broken one yet.
I would change two things on the Grizzlystiks...make them in a light colored wood grain and reduce the diameter of the outsert. Like when we foot a carbon arrow with a pc of alum shaft.
I used a Grizzlystik/Zwickey Delta for this late season doe a few weeks ago. Penetration was thorough, instant, silent, and went 25 yards beyond the deer. (shot from a blind).