As far as pure electronic capability the DACs in the OPPO will outperform the DACs in the 975 just based on the fact that the 975 uses 24 bit DACs and the OPPO uses 32 bit DACs. The capability and future proof-ness of the OPPO is greater than the 975 but...it all depends on whether any source material can use that extra headroom the 32 bit DACs allow for. In the real world dynamic range is limited to around 124db which can be fully "captured" using a 21 bit DAC. CD quality reproduction is done using 16 bits at 44.1khz frequency of capture which is just above the limit of human hearing. Most of us humans will never hear a difference in sound between 16 and 32 bit DACs.