I actually stopped using LAME 320Kbps VBR V0 to rip my favorite songs from my CD's.
AAC has been shown time and time again that it excels over MP3, one can discern an 128 AAC VBR file ripped with Nero over a 128 MP3 file ripped with LAME. The 128 AAC VBR will have greater variation in bit rate sometimes reaching higher bit rates than an equal 128 MP3 VBR file ripped with LAME would not reach. Though I've heard v3.98 has vastly improved, but I doubt it's better than AAC. AAC throws less of parts of the music away for the sake of saving space, between 128Kbps- 160Kbps AAC VBR is better than MP3 versions.
AAC VBR reaches upto 453Kbps on foobar2000's bit rate status bar thingy below while the song, plays.
Try it! Put in a CD, rip with foobar in the converter setup, Select Edit AAC (Nero), in the target quality select: Target Quality (VBR, recommended) and push the slider for quality to best quality, it will reach ~400Kbps.
A much easier way would be to use iTunes, in Import Settings select the AAC encoder and set it to Custom, a dialog box will appear then check the 'Use VBR' box and select bit rate to 320Kbps. Play the ripped song over at foobar, status bit rate thingy and you'll see it easily goes over 400Kbps regulary to reach 455Kbps sometimes. I didn't believe when I read at some sound forums that AAC is slightly better than MP3, that was until I noticed that my 128 AAC VBR ripped files sounded better than my 128 VBR MP3's, this was cemented when I saw the bit rate variances at foobar, that can't be a hoax.
Yes the owners of AAC codec Apple I think totally own MP3, for years to come, OGG is much better though and it's free codec too.
P.S- There's no difference between 320 Kbps VBR V0 and a 320-400 AAC VBR file, this is mostly placebo. This is shown by Fletcher-Munson curves and the biophonic curves which explain human perception of sound and equalisation, though I've not read deeply and they explain equalisation and human perception, not perception of sound quality between lossy files.