I don't think I was clear -- I am using So Fine, top and bottom, most of the time in my domestic machine for both piecing and quilting. But back in the day I used just Dual Duty the same way. Mostly this auction was a LOT of thread, I figure at least 10 years worth of mostly full cones still in their wrappings... I don't remember exactly -- something like 30+ cones, regular "normal" colors plus variegated plus more, it was a steal at $100ish.
(and still working at getting it set up, but I'm hoping my new to me long arm likes it in both places too!)