As you probably can remember I started to use the Tekan II's last year to fill my mechanical itch. I took two deer this year with them and one fell in sight about thirty yards and the buck I shot only went fifty or sixty yards. I have never used the Spitfires but have never liked the way that style looks. Alot of guys use them and like them, but the rear hinge blades do not appeal to me. A friend at work goes on a group hunt with some guys from work and the one guy uses that kind and he told me that they look like to much work to use. After one some times two shots he has out his Allen wrench fixing blades and messing with them. Not saying they are bad, but they do not appeal to me. So when I first seen the two blade rages I liked that style, but do not like the fact that center has the openingin them, I feel you lose strength with this. On the Tekans, you get the same slide back style, but no crossover in the middle for anything to happen. It is also solid the entire length and I think that makes it stronger. I practiced this season with the tekans I had from last year and I shot them a bunch and never had a blade bend or go bad, and 90% of the time I used the same O ring, just roll it forward and good to go. Also like the rages, they are fully open as they go in. Every time I shot into the block the first thing I would check before pulling arrow is the two nice slices in the foam, and they are always there. One more advantage I also like with the Tekans is the main cut on contact tip. The tip alone is 5/8" inch wide, so even if the blades did fail for some reason, I still and making a nice slice on the deer. They are also 100% steel, no soft aluminum in them. I am glad I tried these and they worked well on both of my deer, they both had fully open entrance holes. The deer pic is of the first deer I took with them and it is the entrance hole.