It's solid, can likely withstand abuse, but it doesn't look high end or refined, imo it looks a bit cheap. The jutting out screen is set on a plastic bed, the screen covering feels like plastic not glass, but can't find info on it. The aluminium case feels very sturdy and looks very good, if only the whole dap followed suit, the jutting out back cover is thinner aluminium and doesn't feel as nice or solid as the main body and looks out of place.
I'm not a fan of the side buttons, they are thin and harder to press than some other daps. I also dislike that the buttons on both sides are identical, meaning you have to make sure which way the dap is in your pocket to press correct button. Battery life is average, but that never bothered me. It's slightly heavier than I would like in my pocket personally.
It is responsive, no complaints there, has a few glitches still on latest firmware, but hopefully will be ironed out with further updates. A few times I had to restart the player because the track seeker would stop responding for example. I'm not one for using streaming or online features so they weren't tested.
It sounds great, definitely better than X5ii in every way, tighter definition, bigger sound stage, better separation, etc etc. I did find that there was a very familiar underlying sound style in X7 which was also in the X5ii, I'm not going to describe the sound of X7 other than say it sounds very much like an improved X5ii more than any other dap. X7 is no game changer in terms of sound, in the same price bracket I prefer the sound coming from the Onkyo HA-300, which aside from smaller sound stage takes every other sonic victory to my ears. But as usual it is all subjective. And X7 ultimately sounds very good.
X7 does not excel hugely in any particular field for me, but at the same time has no major flaws, aside from some people saying it has EMI issues with wifi, which if true make it a flop of a product, but I didn't test that so I won't factor that in, and in any case fiio will probably fix that issue in newer units if that is the case. X7 performs above average in all fields tested, if I hadn't factored in price I would give X7 a 4, but with price factored in I give it a 3.5 because I can't justify it's value personally, in saying that, the X7 is unique in it's feature set, so if it's particular features tickle your fancy then it's value is in the eye of the beholder, if that makes sense lol.