Shaft diameter can play a role for sure. Larger diameter shafts, like you see in a lot of really lightweight shafts, provides stiffness and strength. A bigger hoop is stronger than a smaller hoop. Again, that is why it is a prevalent feature on most sub 40, 50 up to 60 gram shafts. Still, you can design smaller diameter shafts that are plenty strong and stiff, but it takes more or different types of materials. My experience is a lot like yours and I do believe there is something to how the diameter affects the overall flex profile and feel of the shaft. The NV, the Ventus are smaller. The old Graphite Design YS Series was that way and was a great shaft, but it no longer exists. You can still have larger diameter shafts that feel and perform great, but the diameter is something to consider, in my opinion. We do measure the diameter on wood shafts we put in our database at 5″, 12″, 20″ down from the butt end and the tip at 3.5″, so we have numbers, but we do not publish. If you have questions on a shafts diameter you can ask me or Jim and if we have measured it, we can at least give you those numbers.
Britt Lindsey