There were a mix of D machines, not just Dorados (which were ECL machines that needed machine room cooling, as well as the earlier generation Dolphin machines, both using the patch panel setup he described. Also Dandelions (sold as the Xerox Star) and a few Altos. The D machines could be booted into any of the three primary environments (Interlisp, Smalltalk, or Cedar/Mesa). I never touched a disk pack (did the Dorados even have them? I think the Dolphins did. The Dandelions had 8 inch floppies — I still have a set with some custom microcode I wrote)
We had a distributed network mail system (grapevine), distributed networked filesystem you mounted directly,etc. The way he describes editing a document it sounded like he was either using an Alto or booted one of these machines in Alto mode.
No terminal rooms? Well yes, this was personal computing, not timesharing.
The speed issues he described suggest he wasn’t using a dorado. My job used Interlisp-D but I did boot into Smalltalk and Cedar sometimes to check them out. The dolphins in particular were particularly underpowered.
It’s often hard to evaluate something on its own terms rather than on the terms you are used to.