vfiber is just a fancy name/sales gimmick. they say its "flexible like urethane, but made of fiberglass". i wouldnt count on it being flexible. but i have seen some good fitting vfiber kits.
idk, as long as you buy from a reputable company you should be good. and that link isnt a place id personally buy from
I wouldnt say like urethane, but the kits are flexible. On a side note, I have
heard that VFiber Orig. is a good company. If Im not mistaken Aerogear has the same kit, and it is made the same "flexible like urethane, but made of fiberglass".