It is a bit expensive, but I find it surprisingly good for it's size with more base than you would expect, it is very portable,the rechargeable battery lasts 12 hours, I use it a lot.I always take when staying in hotels etc.
I looked at it this way, a small portable DAB radio would cost over £100 a good sound dock the same , the jam box works with my iPhone or iPad on bluetoth and is often more convenient than using headphones to get good sound.I can connect any other device (eg old iPod) via the supplied cable.
Even garage band now works with it via Bluetooth.
Hope this helps