I tried them out as I wanted a 200 spined arrow for my 90lb bow. Wasn't overly impressed with durabilty of the shafts, the focs system was decent, but I found the collars bent easy. What I did instead was remove the FOCs system and use some day six inserts I have lying around from my other setup I had checked to see if they fit tossed those on, WOW, is all I will say, they are a very nice arrow with the day six insert setup on them.
That being said, I a sticking to my 250 spine day six arrows and running with them, they area a lot tougher, sure I have broken a few on some bad shots (trying to shoot thru 6" gaps in tree's, etc) and the fletchign catching on one tree sending an arrow sideways into another, they don't usually explode like others but I have had them crack/split the length of the arrow from a sideways impact. They are by far the best/toughest arrow i have used to date, meaning the day six.