We wanted to use it plugged into our iPad for music and the sound is great. You can use either the attached 3.5mm jack (with only a short lead) or you can plug your own cable in if you'd like a longer cable. You have to charge up the battery using USB, but it lasts plenty long enough between charges. This little speaker does the trick!
This USB charging device is great and lasts for ages; providing multiple charges to iPhone/iPad etc. The only downside is the weight of it. It's really heavy. Before getting such a big one (15,000mAh) think about what you'll need it for. If it's just to keep in your bag for emergencies, then it might be better to consider a smaller capacity (and therefore lighter) option.
This is perfect for run and gun. Quickly position height and tilt/pan smoothly to catch the action as it happens. In the past I've used a tripod, so the comparatively small footprint is great. I don't get a sore back after shooting with this for a day, like I do with a shoulder rig.