I did get some details about the PSD, but I've been asked not to share too deeply until the product is released. That said, I can confide that the quality differences do go beyond the ares I provided above, and there are differences all in the preamp section, power supply, volume control and all.
Your update is much appreciated.
Still, being T+A series HV, the PSD 3100 I am sure is a great piece of equipment. Definitely in my “to audition” list