I have experimented no issues working with WAV files on the MAC so far, all track names, art cover and extended file info (like star rating) are there....
Try adding your own artwork to a WAV file. Try copying a few WAV files to a thumb drive and moving them to a different computer in your house. I hope you never have to restore your entire library from a backup, but if so, I don't envy the task if using Mac+WAV. AIFF is optimized for Mac and is basically the same type of bit-for-bit full-rez file as WAV. It is so much easier to deal with on a Mac, and will support all the critical metadata outside of the iTunes interface (which the WAV files depend upon to keep that data organized). You may not have run into problems yet, but I'd once again warn you that this may not always be the case. I have found in the past that WAV are no fun at all to deal with on a MAC.