Well, I I have familiarized my self to the x3 enough to give a fairly accurate overall account of its performance. I have down loaded the newest firmware 3.22, which added a 5 band eq, something that you don't really need if you have accurate headphone and a well mastered source but, apparently, many were clamoring for.
People have reported that various firmware updates have impact the sound of the unit. I can't tell whether it has or not but, at least, it hasn't negatively altered it. What I can say is that regular firmware upgrades has improved upon an already good design. That being said, the build is solid, interface is simple and user friendly and features are adequate. The sound through the headphone jack is, as I have said before, good enough. It won't wow you but it is a nice compact design with just headphones. Now adding a headphone amp and going out of the line out is a different story. This affords you the opportunity to maximize the benefits of what the unit can do. And, for that I am extremely satisfied.
Right now I'm listening to jerry garcia from the Capitol theater 03-01-80 and it is rendering it accurately. This is by far the best jgb live recording available, with a rich and extended sound and this unit keeps those qualities intact.
So for personal listening at the gym, in bed, shopping, or on a hike I can't think of money better spent. It won't break the bank and will put a smile on your face. It takes me back over 30 years when I bought a d6 for recording concerts and would also use it as a walkman, playing back all my just recorded masters. Times are good for music lovers.
Anyway here is what I've been using with the x3: modded fanmusic with upgraded op amp and thinksound ms01 headphones. Owning a system like this would certainly spoil the younger kids because it would cost a lot of green to match this sound with an open air stereo.
To close I should say that although I am impressed with what is offered it does lean a bit to the dry side. But that should be put into context with its cost.