I've used both 5A nylon and woodtips from Millenium, and the nylon sticks are usually of better quality. Recently ordered quite a lot of each and all of the nylons are darker in colour ( = more centre piece of the wood = harder = more durable) compared to the wood tips. Perhaps I just got a good batch, but there is a noticeable difference between the quality of the nylon and the woodtip-versions.