You have a fair point about the PCI-Express 16x slot. Even if you don't wish to use a dedicated graphics card, you're free to drop a PCI-E 1x/2x/4x card instead.
As far as the sound chip goes, there wasn't a lot to report. The sound quality itself when paired with a Cambridge Audio 5.1 set was more than acceptable and the cpu utilisation was low and of little concern. During this review, I didn't have access to a Monitor/TV with inbuilt speakers and so sound over HDMI could not be tested however I had no complaints with the onboard sound.
Thanks for the feedback.