Personally, I do hear the slight difference with lossless, and I wish I could have it for all of my music. However, I can't use it with my iPhone because I have too much music and not enough space, even with 32GB, and I'm not gonna have two versions of every song on my computer, so I stick to iTunes quality, especially since I buy more on iTunes than I do CDs. It does piss me off however, that most iTS music is only 256kbps instead of 320kbps.
