OP here...
Like I already said I haven't towed with a DRW so I can't disagree with any ones personal experiences or opinions. But I do appreciate every ones participation and contributions to (hopefully) a friendly discussion.
I have little doubt if I were to tow my 5er with a DRW I would probably feel a difference. Whether that difference is attributed to the dual wheels or the heavier suspensions of the dually is what I question.
If the opportunity ever presents itself I would welcome a test drive towing our 5er with a DRW. For the record I'm very happy with the TV in my sig.. it tows our 14k GVWR trailer without any stability issues.
I started the thread to better understand what "better stability" towing with a DRW really means and why is it more stable.
This is speculation on my part but from what I have learned so far... the primary function of the dual wheels is to support the increased payloads that the heavier duty suspensions of the DRW can handle. And the feeling of better stability is more the result of the suspension than the dual tires. Just as you would experience a more stable ride towing with 1/2 ton vs a 3/4 ton vs the newer 1 tons.