I'm not sure we're even allowed (by Internet Law) to have a reasonable discussion about audio encoding bitrates, but we'll give it a go :) Yes, these days I use Mac hardware for most of my (home) tasks. I've ended up using the built in iTunes encoders - starting several years ago, it really ramped up its quality (that's according to what I read) and the extra steps of using Lame just wasn't worth it (since I use iTunes to organize my music now). I started encoding my CDs into MP3s in the mid 90's, and those encoders have long been eclipsed in quality. Some may sneer at the use of the iTunes encoder, but since I used it to compare the enocodes to lossless versions (which it can also do), I guess all of my previous statements should be qualified with "the iTunes encoder results" vs. lossless, which was what was easiest for my uses (since I could just click "Create MP3 Version" in iTunes and as long as I had my settings setup right, it would create what I wanted). My gut feel is that these days you'd be hard pressed to tell the difference between encoders, but I haven't tested that. All audio, when encoded using lossy compression, will be very noticeably different when measured on lab equipment - an oscilloscope would be enough to show it, a frequency domain analyzer (which several scopes of course have) makes the differences even more obvious. Though you get into issues of synchronization and whatnot that makes it a pain to ensure you do it right. But there will be differences. I've done all of this, because I have the equipment available and it looked like I was doing work. Human hearing, however, isn't as sensitive as a scope (I don't think I'm saying anything you don't know). The real breakthrough when MP3's caught on, and what I hadn't realized was even possible before then, was its use of the characteristics of human hearing, and knowing what info it could discard without being noticed by anyone but dolphins (and possibly bats). At 128k, AAC (and other encoding methods) are noticeably better than MP3 but as you increase bitrate the differences lessen. I settled on VBR 160k MP3 because MP3's are just more universally playable than AAC (even though I have apple devices, I don't want to be tied to AAC). I did my big self test mostly because I used to have fairly high bitrates, including many lossless out of paranoia, but limited space on my phone, and I simply wanted more music with me all the time, and I found VBR 160k as the sweet spot that - overall - saved tons of space (except for some albu