Is the SACD Format Flawed?

I have just received my new APL 3910 and am loving it already with less than 20 hours on it! As this is a multi format player, I am now looking into SACDs.

There are some in the industry including some respected non mainstream reviewers and people in the industry I respect who say they hear something fundamentally wrong with SACDs and the DSD format. I haven't had enough exposure to come to my own conclusions, but would like to know what others think.