I have been using ACCs for over ten years. I think they are very durable especially when you compare them to thin walled fat aluminum shafts. I shoot 3-60s and 3-49s. My 360s weigh in at 403 grains with feathers and screw-in 100 grain points. I don't use the 3-49s much anymore, previously used them for 3D shoots years back but I just stick with the 3-60s now to keep it simple. However the 3-49s with glue in tips are a lot lighter and shoot about 20 fps faster than the 3-60s.

To calculate FOC measure the total length of your arrow and then mark the center point. Balance your arrow on a straight edge, when you find the point where your arrow balances level mark it. Now measure the distance between the two. Figure the percentage of that distance in respect to the total length of the arrow and that will give you you % FOC.

You can use the equation below to figure out FOC

(Midpoint of Arrow to Balance Point of Arrow)" X
(Total Lenth of Arrow)" =100