Thirded... After some months of consideration and testing, I decided I
couldn't tell the difference between CD and 320kbps, LAME-encoded mp3s

If you want to test, put some stuff with nice harsh harmonics thru the
compression. Sharp-edged waveforms with lots of high harmonics are a
good test of just how well the signal can be reconstructed.

A co-worker did this with a series of different encoders. Of that set,
LAME was one of the best for the pulse waveforms he was testing.
Unfortunately I don't remember where he posted the results of that
study; I'll try to dig that info out again.