Do you believe Ouyang Feng could have won the 2nd Huashan tournament if he had stumbled upon QKDNY or Taiji Fist instead of a corrupted 9 Yin?
Both QKDNY and Taiji are external arts. It was also the weirdness of OYF's external arts after he studied the corrupted 9 Yin that allowed him to win. I believe QKDNY should be a superior substitute to crazy 9 Yin.
Another reason that allowed OYF to win was because his pressure points changed places so he could take additional hits without losing. But one can argue that he only took those extra hits due to his crazed mental state and negligence of defense, by studying QKDNY he would still retain his sanity as well as drastically improve his martial arts.
The poll asks for QKDNY, but feel free to post your comments regarding Taiji too. Can Taiji Sword wielded by OYF defeat Dog Beating Stick? I think it might end in a draw, it would still take a long time for Ouyang to figure out the counters, but Taiji Sword, being a more defensive martial art should allow him to survive at least.
I think Taiji Fist will make him fight to a draw, to me it seems like Taiji can defeat weaker opponents in a spectacular fashion but it's much harder to use the force of someone of your inner power and experience against himself.