This seems like a fair match up compared to the stupid Goku vs anyone in the NV. Kaioken and Gates both boost physical strength and speed, and both have painful after effects. Which is the better ability?
Kaioken reminds me more of what Naruto did to Kaguya with the five tails. But If I had to choose between these two I would go with the gates. Simply because the gates have shown more effects on the body then Kaioken. Goku never used Kaioken much to make me care. It had so much potential. I don't get why he never used it when he was Super Sayain 3.