burnie,
Some on here will be ripped at me for posting this, but it's the truth.

Here it is, my shooting buddy has GT arrows spined the same as my arrows. I have shot his GT's (with regular 4" vanes) on several occasions and they group nice and tight at twenty yards for me.

Today after work we got together and shot again. This time I tried some of the same GT's that have been fletched with the Quick-spins. The best group I could get with them at 20 yards was about 4". AND those groups were 4-5 inches low at twenty yards. I'll never buy any.

Just my own honest experience.
Kev