As for titanium, there isn't a lot of knowledge about titanium because of the expenses of the raw material and the labor required. There is debate as to whether it makes any sense to use butted tubing. It might be that the cost is great and the benefit is small. It might also be that the extent of butting is too small to make a difference. So when I see a straight gauge titanium frame, I don't poopoo it as lesser than a butted titanium frame.