SA6's
having owned several of these phones, I agree that the Triple.Fi's and the SA6's are at the top of the chain.
However, your "if" regarding the Triple.Fi's, ("if you can get a good fit...") is one of the reasons why I think the SA6's are superior. The TF's are just way too clunky, akward, difficult to fit properly and therefore the SQ suffers measurably. Most frustratingly, they are incompatible with Shure foamies, which could really help matters otherwise.
The SA6's, by contrast, are tiny and light and far easier to fit with sufficient stability that you can walk, run, whatever, and forget that they are on.
Even with a good fit, I still found the SA6's to have a naturalness and musicality that the the Fi's lacked by comparison. For me, "sparkle" is the the word that comes to mind with the SA6's. The TF's lacked some of that, and sounded a little more dull to me.