fsmithjack,
I actually ordered the Uptone Audio JS-2 and canceled my order. So much of this hobby is psychological to me, so I order the S60 to prevent from wondering if the JS-2 was the correct choice.
Honesty, I can't tell you what adding the S60 is doing. I added the S60, S30, and K10 at the same time. I went from streaming music to listening to ripped CDs. It was immediately apparent that music had more body, detail, and more open.