Personally, I feel the 22KHz frequency limit is only the tip of the iceberg (and may not be important at all).

The problem with the Nyquist theorem of wave sampling (that any wave can be reconstructed perfectly by sampling at twice the maximum frequency you wish to capture) is that it's only true on paper...  Actually getting a piece of hardware (DAC) to reconstruct the exact input wave from a 16bit/44.1KHz sample is another kettle of fish entirely.  There are a squillion and one obstacles in the path to perfect D-to-A.  Things have come along quite a ways since the dawn of CD, but my ears tell me they still have a way to go (and I'm not sure they're ever going to implement Redbook CD to its theoretical potential).

Dunc

P.S. - And we both have the same DAC, which IME is one of the best out there!