I think to be more ideal the shape should be more rounded near the nose and then straightening more perpendicular to the blades at the root. This would create more of an airfoil around the cone rather than just deflecting. Also, in my case if the root taper of the blades were closer to the cone I think more of the deflected wind would be directed over the steep angle and help start up even more in lower winds. My first goal was to make it look finished and in proportion, I'm happy with that. I think very light weight high speed blades (as shown on the link previous) would definetly be more likely to be loaded down by a cone with large area and or weight out of proportion to the blades. The argument will go on I'm sure as to improved performance or not but to be fair all variables for each mill and hub design should be considered in each case. From a marketing standpoint if the engineers get the design of a nose cone close to or same as the performance without it and it looks decent you can bet they'll leave it on, if they don't their competitors will. Ever known people to buy speakers that "look" good no matter that their ears or specs. may tell them otherwise ? My rotor still starts with a few seconds of 5 mph wind, it will be interesting one way or the other if I can notice a difference in performance up to furling winds of 30 mph. Like driving a clean car, sure seems to go better and the neighbors may appreciate it a little more besides. Thanks for all the comments and feedback, interesting stuff. Dave B.