I started shooting them last year and I was told you can even go no offset. The guy at my local bow shop does this and I went with only a 1 degree offset. They fly like a charm. He told me anything over 2/3 like you mentioned actually reduces performance (according to NAP). This was from him, not me, but I trust him more than anyone for my bow hunting needs.

Edit ---- I found this on NAP's site, good stuff:
http://www.newarchery.com/press/info...actoryTech.doc

My quikspins went through an elk and a mule deer last year and they will be on my arrows this year. They have a new 2.25" inch that is much lighter and still performs just as good.

I shot the snot out of these last year and here is my observations:

- little bit louder, but nothing I shot last year seem to noticed or jump
- I shoot broadheads with practice blades only and actually got about 1 inch deeper penetration into my block target that with standard GoldTip vanes
- my groups got better with them over time, but barely and could have been me just shooting more and more

Overall, I liked the added penetration into my target, especially since I chase the bigger game