Samsung Exynos 7570 Advantages
More modern manufacturing process (14nm vs 20nm)
Lower TDP (4W vs 5W)
Released 1 years and 3 months late
MediaTek Helio X20 Advantages
Better graphics card performance FLOPS (0.0998 TFLOPS vs 0.0208 TFLOPS )
Larger memory bandwidth (12.8GB/s vs 4.2GB/s)
Higher Frequency (2100MHz vs 1400MHz)