i would agree there is considerable confusion oversimplification and misunderstanding regarding what goes into a dac and what inside a dac contributes to how it sounds as a finished product -- r2r or delta-sigma chip-based d/a conversion is but one of several key factors...
here is a place to start... an old thread from several years back, you can page down and scan for my comments trying to clarify the subject
alternatively, watch this video
hope this helps