Glen,I've been using the NAP Spitfire Pro's for years with excellant results(100grs.).Great mech-heads.They worked so well,that I just had to try out the new XP's.They look great,fly like fieldpoints,NAP's usual quality.One problem,the replacement blades are not available.You can get them though their web sight,but thats a pain in the neck and it's pricey.I don't know if you can use the replacement blades for the Scorpion XP,cause they have a 1-1/4in cut,and the Spitfires have a 1-1/2 cut.This does present a problem to me,because I change out blades(new) after every shot when I'm hunting.If I would of known of this,I would of stayed with the Spitfire Pro's,Scorpion XP's or the Shockwaves...Bob