I voted (against my best judgement) Fuze. I don't think it sounds 'better' than my other players, but it has more to offer. The Apple and Sony sound 'better' in some ways: smoother, and in the case of the Apple, less hiss. But, the Fuze has one thing in its favour: rockbox. And, it performs much better with hard to drive iems than any Sony, Cowon, Apple, etc. I DO not like the Fuze without rockbox however. It is rubbish, has rubbish code support, stupid controls, a stupid light, and pretentious marketing.
The S:Flo also drives iems very nicely, but unless firmware is fixed, I'd stay away. Lacking gapless playback is huge.
With sensitive iems, a DAP that hisses is hard to manage. So, ixnay on the Sony (unless you don't mind the sound of wind). Cowon don't hiss too badly, but they have pretty shoddy lowΩ peformance, with compressed stereo images and audibly boomy bass. I sold mine because of those two reasons.
If the Fuze was as 'smooth' as the iPod or Sony, I'd love it. As it is, it stays because of Rockbox.