My X3 arrived today. I put some of my favorite FLACs on a card and compared the X3 to my current player, a Colorfly C4. I only used my primary headphones, orthodynamic Smeggy Thunderpants (50 ohm). These are low sensitivity headphones, though not as low as some others.
Bass: Same quantity. The X3 is better controlled which is important as the Thunderpants can get a bit flabby with some amplification.
Mids: More difference here. The Colorfly is more prominent (I think this is why some people have called the X3 "thin"). I prefer the X3. If you have compared electrostatic phones to dynamic ones you will know what I am talking about. The X3 is an electrostatic, the Colorfly a dynamic. To me this results in a less fatiguing sound.
Highs: Similar in tonal balance. The X3 is less edgy (and the Colorfly is itself one of the smoother DAPs).
Imaging: The X3 is more precisely focused, the Colorfly more diffuse. Not enough of a difference to be very significant.
Power: X3 wins hands down. Set to high gain, has much more headroom and shows no signs of strain at very high levels.
Looks: While the X3 is a very nice looking unit and substantially made, the Colorfly wins hands down. Can't win everything
UI: Haven't really had much time to play with the X3 but the Colorfly has an extremely basic UI and it's hard to believe the X3 won't be better.
Storage: Colorfly has 32GB internal and can take a 32GB SD. X3 has 8GB internal and can cake a 64GB microSD.
Convenience: X3 is much smaller so better on planes which is where I use a DAP. Only downside is the X3 only has a 1/8" jack (Colorfly has a 1/4" also). Anyone know of a well made but not over-priced flexible 14" to 1/8" adapter? I could make my own but 1/4" inline jacks are not too common.
Conclusion: Except for looks except for looks and the lack of a 1/4" jack (which wouldn't have fit in the case) the X3 wins in every instance. So a $200 DAP beats (at least with my 'phones' and my tastes) a $750 one. I will be selling my Colorfly. I will start with using a 32GB card and will go to a 64GB with the next firmware release,