Thank you damblack, In tests, no format is holding complete metadata, perhaps this is a bug that needs fixing. MP3 does the best, but MP3 is not the "best" quality format,. WAV (lossless) is better, and further it is accepted that Apple Lossless (M4A) is the best lossless format available right now. Furthermore have you noticed that S1 (Pro) will not import AIFF but will import MP3 and FLAC? Right now my workflow is FLAC in and WAV out. Then I am using "Master for iTunes", to convert to M4A and then import into iTunes to manage all metadata, even after entering all metadata into S1.