[lin0003]

The Clip and Fuze look like nice little budget players. What is it that sets the X3 so far apart from them?

The DAC section and the amp. The Sansa DACs are most likely not so good ones like ones on phones, but the X3 has a WM8740 which is quite a good chip that is used on the much more expensive AK100. There is also a dedicated amp section which adds more sound stage, clarity, separation and so on. Even though it doesn't touch something like the DX100, IMO it is better than a stock AK100 and it has low impedance so you can also use it with sensitive IEMs without problems. It is a bit dark which is good for the slightly harsh treble of the HE400.