Qualcomm Snapdragon 625 Advantages
Better graphics card performance FLOPS (0.1248 TFLOPS vs 0.0998 TFLOPS )
More modern manufacturing process (14nm vs 20nm)
Released 9 months late
MediaTek Helio X20 Advantages
Larger memory bandwidth (12.8GB/s vs 7.46GB/s)
Higher Frequency (2100MHz vs 2000MHz)