Zelda has a review of the X3 over on Head-Fi. From the review it is clearly an entry level DAP priced at around $100. There is some completion in the $75-$150 price range so you are looking for an entry point for HiFi DAPs you may want search my site for reviews of competitive products. I do like the fact that it has two microSD slots.
Pros – Sound Quality: detail, transparency, air, separation; Build quality; Very portable; 2 micro SD slots; Good synergy; Solid firmware
Cons – Battery; Buttons layout; OLED screen is useless under the sun; Prone to scratches