Without any real life experience with these processors the only reason I’d pay the extra money (2x) for the 8805 over 7705 is that the 8805 has 13.2 channels and the 7705 has 11.2.
All else being equal ... I doubt I could tell the difference in a double bind test ... (I’m sure there are others who will claim they can and I’m happy to let them do so ...)
Although I make fun of it ... all the great marketing, I mean engineering, does give me that warm and fuzzy .... just knowing all that great stufff is in the box. Maybe someday someone will convince me it makes a sense-able difference.
One more note: the 8805 is the only processor in 15+ channel, sub $5000 market (USD) that I trust to work out of the box at least at this moment in time. And with all I’ve said above is on my short list of preprossesor I’m thinking about