I have both of these hardware devices. If i run the KODI 16 version that comes installed on the android system when you buy these units, they play audio/video PERFECTLY in sync.
However, when i then boot into the CoreElec it appears that the video falls further and further behind the audio. If i disable the Hardware Acceleration for Mp2, the audio/video stays in sync, but the video is quite jerky.
Video decoder : am-mpeg2 (HW)
1280x720p, 1.78 AR, 59.940 FPS
PT-AC3, 8 bits 48,000 hz, 384 kb/s
Pixel Format : 10bit, YUV422