Hi Fredk,
It's not the MP3 at 320 kbps that's at fault, it's the original source recording that's no good. I don't know that particular album, but if you get the CD version (assuming the mastering source was the original), then the CD will sound equally disappointing.
MP3 at 320 kbps is remarkably transparent for all but a few rare musical instruments, such as castinets and some other percussion. In the codec transparency tests I participated in some years ago with a big group of panelists at the NRC in Ottawa (the same tests were repeated in the UK and Australia with the same A/B/X protocol and test selections), you had to go to lower data rates with MP3 before any audible artifacts showed up. We did about ten different codecs (some were clearly inferior and were rejected). But MP3 at 320 kbps and a couple of others (a Franhauffer codec from Germany as well) were excellent.
Regards,
Alan
