A while back I went the player with DAC route and had this experience: I had three DACs, an Adcom GDA-700 with HDCD, a PS Audio (forgot model #) with HDCD and a Bitstream (forget model #) without HDCD. The Bitstream DAC was head and shoulders above the other two DACs when decoding standard cds. But when a cd encoded with HDCD was played the Adcom won hands down. On well recorded cds the difference wasn't subtle. I used several different cd players as transports, one of which decoded HDCD and as a stand alone player it bested the Bitstream when an HDCD disk was the subject of comparison. I feel there really is a difference, spatial clues are more evident, smoother quality to music without any loss of detail or resolution.
Of course technology will advance and new developments will make HDCD obsolete as well as cd at some point. Until then I'll make sure I have some means to decode HDCDs.