This is not an attempt to settle the discussion PCM vs DSD -- aka DVD-A vs SACD --, but simply a request for some factual information for which I have searched the web in vain.
It would prima facie appear that 1-bit delta-sigma is capable of representing higher amplitudes at low frequencies than at high frequencies: 0 represents a decrease in amplitude, and 1 an increase in amplitude, so at low frequencies we can go on increasing (or decreasing) the amplitude for a longer time than we can at high frequencies. The amplitude that can be represented is thus inversely proportional to the frequency.
However, SACD players can reproduce the same amplitude throughout the frequency range, so there is apparently something I have overlooked.
I'm sure there is a member of this site who knows the answer. A reference to a good primer on DSD would also be appreciated.