Pros: Sound quality
Cons: Some minor issues with the volume setting in relation to the lockscreen
I owned the X5 since 3 weeks when I wrote this mini-review, and there is absolutely not regret in relation to that purchase..
The design is not really my piece of cake, but this is not supposed to be a judgement, because I can imagine that others will especially like the X5 for it's looks.
The sound is as good as you could expect it from a portable unit in that Price range. The sound stage is stable, the background as dark as I could wish, and there is no recognizable coloration and distortion. Just make sure your headphone is on the rather higher-efficiency side. So in-ears as i.e. my Miles Davis Trumpet obviously go very well, but also full-size cans as my AH-D7100 sound really great.
More about my impressions, especially concerning the user interface in relation to the volume settings and lockscreen here.