MediaTek MT6739 Advantages
Released 2 years and 4 months late
MediaTek Helio X20 Advantages
Better graphics card performance FLOPS (0.0998 TFLOPS vs 0.0091 TFLOPS )
Larger memory bandwidth (12.8GB/s vs 6.4GB/s)
Higher Frequency (2100MHz vs 1500MHz)
More modern manufacturing process (20nm vs 28nm)