samsung s9 is flagshil smartphone from samsung with some top notch specifications and features and which definitely wins over oneplus 6 which is latest smartphone from the oneplus which has huge popularity among buyers and it comes to reasonable price as compared to samsung galaxy s9 .
I feel the two are very close, price point is a bigger factor for most, also there is less bloatware with One+6, thus another reason for performance enhancement. To me IPX ratings are great, but OnePlus is water resistant enough to withstand, short of dropping it in the ocean. Just doesn't have an official rating. My money goes to One+ simply on ability to customize it far more than the Sansung and the 300 dollar less price tag.