Have heard the same, that stock cable is not bad at all, but also heard that the higher grade one make a huge difference, seems that T1 are getting lots of benefits from it.
I'm usualy not afraid on re-cabling my headphones ( done many in the pass) but I feel the cable in the T1 is very good already. The only reason I would do it is to get a more flexible cable. The best person to talk too is the same guy that you learn on how to open them zombiex. He does recable I believe and if I not mistaking his own T1 still have the stock cable