I have a couple of them (yeah, I'm a geek). Pros are that the charger is nicely integrated; cords come into the bag in padded pouches. You can see the power level on the outside, it can charge four things at a time, and you can swap out battery packs on the go. At CES, Powerbag was the only thing that kept my devices going. With two 6000mAh packs, all my devices were fully charged all day long.
Several of the people traveling with me constantly made use of my bag as well - so I guess the only downside is that there is no coin slot to make them pay
That said; if you are a fan of high(er) end luggage, the bag will seem like a bit of a downgrade. It is nowhere near the quality of say, Tumi. Lots of pockets though, and some smart design features like the power plug being accessible on the outside, and a pocket to store the AC adapter (which is worldwide compatible).