Do not expect the sound quality luxury with this price, but it is more than adequate for this. There is distortion when you put hard, but it's still acceptable to my taste. The bass is present, the sound is stereo. The volume is loud enough to hear even outdoors. But I repeat, if you need a portable speaker with high sound quality, so do not buy it.
Autonomy is acceptable (4-5 fortunes around, more if you listen not strong), but what is good is that the battery is exchangeable, and even better, you can find high capacity compatible batteries (up to 2500 mAh against 600 mAh in the original) on eBay BL-5C model (yes, the model of the old Nokia phone) to less than 10.
I have not tested the reading SD card or USB key because I do not buy it for these features, but apparently this is not the best, since there is no is no way screen navigate to folders.
I bought this speaker to listen to music in the shower, and for casual outings and I'm pretty happy with this purchase.
