As of now, Google Drive & youTube play videos back the best! While Documents and photos are working fine on One Drive - MP4 file for video/audio play back are not - such a popular format for all videos is not fully supported on One Drive. I get audio drop outs especially in the music sections (consistently) no such problem with Google Apps or when i download the MP4 files from One Drive to my Windows 10 Desktop computer- it plays fine, without the dropouts.