I bought some of them in a 500 spine. I also have some easton epics in 500 spine. The epics seem to shoot much better than the T.O's. Also, I have found the T.O's to be much more fragile than the epics. I have a backstop behind my target that is made out several pieces of old conveyor belt material. I have hit it with nearly every arrow I have(not a great shot obviously) and they all just stick in about 3/8" and are easy to pull out. I hit it with the T.O's and it broke them right behind the insert(from about 40 yds).
Don't get me wrong, they shoot ok but not as good as some of the other arrows I've tried.
Dave