I bought one a month or 2 ago. I love it. Works great whenever I have used it.
The pack itself charges with the same plug in that your phone does so I just charge it randomly from my phone's wall charger. It also includes cables to charge it but I haven't even bothered since I have plenty of phone chargers all over lol. The cable that goes from the pack to the phone is short but it comes with a bunch of different tips so you can change it to fit other devices (ipods, older phones, and probably other random stuff too). It also charges the phone as fast as a wall charger does which is awesome. I watched video on my plane ride home yesterday and it out charged the drain of the phone no problem. I would say the 5600 is plenty of extra juice and it is a fairly small package with minimal weight.
My only negative is I would like to find a longer usb to micro usb that will charge fast like the included one does. If you take just a normal one like what is included with your phone it charges like its plugged into usb and not the wall. So if anyone has any information on that or tips let me know!