Stingers, fly great, and LIFETIME GUARANTEE. They don't spin, send them to Mike. You hit a rock, tree, bone, whatever, Mike at Magnus sends you a new head. As for re-sharpening, simple with the $7 Accusharp. I shoot the 125's, and they are amazing. The 100 should actually be easier to tune and shoot. To sum these heads up:
1. Fly great
2. Cut on contact
3. Easily re-sharpenable
4. SS blades
5. Razor sharp, right out of the package
6. Lifetime Guarantee
Is there anything else a broadhead needs to be?

Oh, and 5 shot gave all of the Stingers very high scores.

JMAC