Qualcomm Snapdragon 685 Advantages
Larger memory bandwidth (17GB/s vs 14.9GB/s)
Higher Frequency (2800MHz vs 2200MHz)
More modern manufacturing process (6nm vs 11nm)
Released 2 years and 3 months late
Qualcomm Snapdragon 678 Advantages
Better graphics card performance FLOPS (0.3244 TFLOPS vs 0.2432 TFLOPS )