New to the Audiophile scene BUT! I do have some experience with some of the players,
The line of iPods/iPhones to Sony's and a couple other misc players. I have to say that this thread is somewhat responsible for my new decision on player!
Since I moved to the Philippines from the USA finding the Sansa Fuze with v2 firmware was not an easy task. Once I received it i immediately turned it on and hooked up my Sennheizer CX-870's to it and heard beautiful sounds that were rich and clear.
I have been using my iPhone 4s + CX-870's + Fiio E11 and nothing I did even with the EQu app got rid of some real ear sores that the iPhone 4s has due to the change in there audio chip. HOW FRUSTRATING!!
I tested the Sansa with a combination of my CX-870's CX-215's HD-201's + FIIO E11 and was very relieved to no longer hear this strange faint high pitched noise/hiss I was getting from the iPhone 4s.
Out of the box however the EQ settings turned the beautiful clear sounds into something obviously digitally modified almost muddy (at least to me). So with a little bit of digging I decided it was time to Rockbox the device and immediately noticed even MORE improvement and the Rockbox EQ is very feature rich almost need a degree to fully utilize it, but with enough play you can get it to do exactly what you want. Theming is nice etc.. etc..
This little player is AMAZING!! Kills any other player I have tried NOTE: I have not tried any cowon's, or HIFIman's *yet

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MediaMonkey is a perfect application to use with this to sync your music library as well (Flac support!!)
I am looking forward to my next upgrade on headphones that I feel very confidant in purchasing now that I have a solid audio rig for my portable work use. (HD-650's for home and IE8's for work)
In short, The SANSA Fuze is a winner for me, I will be writing an article at some point soon to help point the other lost iPhone 4s users in the right direction. Now to hack me a 64GB MicroSD card to work with this thing and bring my flacs with me! 100% satisfied!
OH! I no longer need the FIIO E11 for my work setup because of this player. The FIIO E11 actually gave me TOOOO much amplification and started destroying my sound (unless i adjusted the volume settings on the player and FIIO E11 until it was perfect, but plugging directly into the player I was able to achieve the same results)
Hope this helps anyone who's interested in a SANSA (I imagine the Clip+ will achieve similar results)