We have one of those portable speaker things and use it to play music via a thumb drive/memory pen. It's great, long battery life, compact, neat and it gives a very rich sound for something of its dimensions.
There are two problems however.
The first is its default set for the volume. Were the guys who set this completely deaf? As soon as you power up it booms out and even if you're expecting it, it will still make you jump. God knows what our neighbours must think.
The second is that it uses the same buttons to skip tracks (long hold) and to adjust volume (short press). And that compounds the first problem for when you try and decrease the volume you either end up skipping tracks at Concord levels of decibels or you end up with finger fatigue by stabbing the "down" button.
Not a good design feature.