Is there a downfall to charging with a computer? Just curious.
Not as far as the actual charging is concerned, no. I do it myself very occasionally if the computer is the only power source available.
Basically you've got a circuit inside the battery that controls the charge shutoff, that they probably manufacture for less than $1 in China. There there's another circuit in the charging dongle that is supposed to provide safety and a secondary charging indication that might cost them about the same to make. The USB port on your computer is also a pretty simple part, but that is plugged into your computer's power supply and a data bus somewhere. Should something bad happen to the circuits that you plug into your computer it might at best kill your USB ports, or in the absolute worst case scenario kill your entire computer. As unlikely as it is, I don't think all of us feel entirely comfortable about recommending this.
Strangely (or funnily) enough, the main source of trouble is probably the Cheap USB wall adapters which are far more likely fail catastrophically, however at least your computer and data are safe. A high quality USB plug pack is the preferred method, so the lack of a plug pack in that kit is probably a good thing.
If you are currently using your computer for charging you don't need to be too concerned, but do consider getting a quality power supply with USB outlets at some point. You can also get power boards now that have two or more USB power outlets on them and it's a good option to minimise clutter for some people.