We've never had much success in staging Jin Yong vs. Gu Long character martial arts comparisons on this forum (mostly owing to the writing styles of the two authors being too different), and I half expect this thread to fail too, but I've selected two well-known and powerful characters (but neither so powerful that the fight would be one-sided either way) from the Jin Yong and Gu Long universes for a showdown.
When I was a kid watching TVB wuxia dramas for the first time, I believed that no other swordsman could match Sai Mun Chui Sheut and no other hand-to-hand fighter could match Kiu Fung. They both defeated most of their opponents with the greatest of ease, and yet each did occasionally encounter an expert who could equal or even surpass them.
Kiu Fung fought a number of swordsmen in DGSD, but never one who had mastery of the sword at a level like Sai Mun Chui Sheut. Likewise, Sai Mun Chui Sheut fought some impressive hand-to-hand fighters (including his buddy Luk Siu Fung), but no one who could project powerful LDA palms like Kiu Fung.
I think this would be a good match.
So...with both fighters at optimum conditions on neutral ground, how would Kiu Fung vs. Sai Mun Chui Sheut go?
I predict a long, brutal fight, and at the end, Kiu Fung will have the tip of Sai Mun's sword stuck in his chest while Sai Mun suffers devastating internal injuries.