RecordStoreReview.com : AAC vs. MP3 comparision. Is it as good as CD?

I am trying to find out if AAC is really that much better than mp3's. I already have burned my cd collection to mp3's and the thought of going back to reburn at a better bit rate does not fill me with joy. Also my wife may be ticked off that I will not be present for another three months of audio extraction isolation.