To make it short and precise: I am very impressed with this little speaker. Tested it only once (cannot say anything about endurance) but immediately grabbed my laptop to leave this review. The speaker is very small and has an impressive sound (for its size). Perfect for traveling if you mainly listen to music inside the house. Sound quality is absolutely fine... again, I must say for its size.. if you want/need lots of bass you will have to buy a bigger one or listen to your music with earphones. No batteries needed which is plus in my case as I always travel with my laptop, however, it may be a negative point if you do not have access to a USB port as you cannot simply buy new batteries. The speaker comes without an instruction manual. I think it's a fair point as you only connect it, turn it on (there is only one switch), open it up (hamburger design) and are good to go. There is no volume control on the speaker... i.e. you will have to control volume at the source (mp3-player, phone, laptop etc). Poor wrapping and translation which I just mention to make this review more or less complete.
+ super small
+ sound volume/quality is quite impressive (for the small size)
+ easy to use (plug and play)
+ compact and sturdy design - I doubt you can possibly break this thing (unless stepping on it maybe).. dropping it should be absolutely fine
+/- no batteries needed (charged via USB)
- (obviously) no stereo sound (single speaker)
- wrapping, no manual, bad translation on the box (doubt you'll need to read much... but should be mentioned here)