Frauenhofer MP3 is not at all the same as AAC. Two totally different codecs. Do the comparison with AAC 256 VBR or AAC 320 CBR and lossless. Make sure you line level match. I guarantee you that you won't hear a difference, even with the best equipment made. Your guests won't hear a difference either, assuming they are human. If you never do the test, you'll never know. I've done it.
By the way, the difference between higher bitrate compressed audio and lossless has nothing to do with upper frequencies. Once you get over around 128 with AAC, the frequency response is identical. The difference is only artifacting... Once you get beyond the place where artifacting happens, the sound is identical.
There are definite advantages to smaller file sizes for long term storage. A smaller file is less likely to suffer from random data corruption. It's easier to back up and stream over wifi. There's more to it than just hard drive space.
Edited by bigshot - 2/27/13 at 11:43am