Depends upon your needs. Do you play resource intensive games?? or Do you prefer the latest and greatest hardware and software features??? or Do you want the Oxygen OS???, then you might wanna pay extra and buy the Oneplus 8. But if you don't care about those stuff and need a Samsung flagship, a headphone jack, like S Pen, prefer trading off new features for a cheaper price, then buy a Note 9.(Note 9 is already 2 years old, so I might not be surprised if it doesen't receive the android 11 update)