Zd542, both players use Burr Brown DACs but I do believe the Sony chip has much more impressive technical prowess. The spec sheet for the PCM-1796 will reveal that. It's one of BB's top-of-the-line chipsets whereas the PCM-1732 was decent but more noteworthy because of its ability to also decode HDCD.
Like you mention, the analog stage is also very critical in the performance of the DA section. However, I think it's safe to assume that the PCM-1732 (RCD-1072) falls short against the technical performance of the Sony player.