*Anything* you flash to your phone carries a risk (however minute) that it'll brick the device. The root method may be different, but for the most part ROM flashing is the same across any Android device.
IMPORTANT: Check your device model, since there are two variants of the Sprint S4 out there (SPH-L720 and SPH-L720T). The 720T doesn't work with all ROMs, and (last I checked) you lose the Spark connectivity, but 1x/3G/LTE will still work. I have one of the old models before Sprint started rolling out Spark, so I haven't really been keeping up with that part of it.
Look! A distraction!