The Oppo Find X9 has been found to have over 50% less performance under sustained load in a stress test. Other models, such as the Oppo Find X9 Ultra, have been reviewed by various outlets, with some considering it a top smartphone, while others note an overlooked weakness. The performance of the Oppo Find X9 under stress is the only specific issue reported, with other information about the device and its variants being more general in nature.