I think people interested in AAC probably aren't using it at low bitrates, so I'm not sure how meaningful that is. At more reasonable bitrates for people who c

I think people interested in AAC probably aren't using it at low bitrates, so I'm not sure how meaningful that is. At more reasonable bitrates for people who care about quality (and thus are using AAC over MP3 in the first place) I don't think there's enough difference to discern on most listening devices - but I've not done any sort of scientific testing between the two myself, so I could very well be wrong on this. FLAC vs ALAC is a much stronger argument IMO - though elsewhere in these comments there's a suggestion that ALAC was chosen as it was cheaper to decode on Apple's hardware at the time, which if true would be a reasonable motivation.