Actually on a Mac with iTunes, if you want uncompressed music files, AIFF is your choice, not WAV. AIFF can retain all metadata, including album covers if you paste them in.
My 2500-album library is a mix of ALAC mainly, with about 10% as AIFF. And I've tested several albums over the past few years, having each as both ALAC and AIFF...and I don't believe there's any difference.
What helps keep the compressed ALAC and uncompressed AIFF sound the same as been powerful enough music servers which can decompress the ALAC files quickly.
My 2500-album library is a mix of ALAC mainly, with about 10% as AIFF. And I've tested several albums over the past few years, having each as both ALAC and AIFF...and I don't believe there's any difference.
What helps keep the compressed ALAC and uncompressed AIFF sound the same as been powerful enough music servers which can decompress the ALAC files quickly.