WC strings will stretch right out of the package. dont let anyone tell you otherwise. make sure you shoot about 20 shots before setting your peep, then set peep, then shoot 20-50 more before you leave your pro shop.
WC strings used to be the best, but Tom Neely has started his own company, and I assure you Tom is more consistently making a better string. I say more consistently, because WC has people making strings that don't even shoot a bow! With all that said, I ordered myself a WC string the other day. I certainly am not a good enough archer to notice the difference in my shot, so I went with the cheaper of the two.