I've been using the 600 version of the DT shafts for a short while. So far everything is going well. One observation is the inserts that came with the shafts feel 'loose' during the installation with the low temp (blue) hot melt. With GT shafts and inserts, there is a small amount of resistance during the last eighth of an inch of movement just before the collar of the insert contacts the end of the shaft. This small amount of press fit makes it easy for me to unscrew the point insertion tool I use before things have cooled down. With the DT shafts, the inserts go in loose all the way to the collar and are so loose I cannot simply unscrew the insertion tool--turning the tool also rotates the insert. Instead, I have to grab the end of the shaft and insert with a pair of pliers, and then unscrew the tool. Or let things cool down. Not saying this is a shaft issue, could be undersized inserts. But it's annoying. So far, the inserts stay put after cooling. None have pulled out in targets, etc. Seen anything like this, Big Jim?