I took a tour of their factory in February... I don't recall specifics of what was built with what, but I do recall being told that in some places, they used a fibre product that was sort of a glass rope, rather than the usual cloth. If I recall correctly, the spars were one place. I wish I could remember the name of the glass rope-like stuff for you. As I recall, they said they used it because it make it faster and cheaper to make those parts that way, it wasnt an appropriate technique for thin/short shapes, and I don't think he commented on if it made for a lighter,heavier,stronger or weaker product. (I wish I'd thought to ask at time, but I'd guess its strength neutral or stronger, but heavier)