Respecting the opinion of some I believe that there is no audible difference between FLAC, ALAC, WAV or AIFF. If you are using iTunes then your options, without a third party software involved, are WAV, AIFF or ALAC. When it comes to metadata my opinion is that eliminates WAV. My library is AIFF. Today I simply think there is no issue or concern with storage space and see virtually no reason for even lossless compressed files. However, looking to the future with music servers and digital players being offered by many manufacturers, FLAC may be the very best option at this time for portability and compatibility.