Do bear in mind that you loose high speed sync with the Nissin, which is important when using it as fill flash in outdoor daylight. If that doesn't concern you then you're fine.
Also, like what tecnica said, the flash duration is very short, so when the flash is the main light source (in the dark), the aperture is actually the limiting factor, and the smaller the aperture you use, the harder the flash must fire, and the shorter distance it can reach. And due to this very short flash duration, it will be able to freeze any motion you have. Flash sync speed is typically from 1/60 - 1/250" depending on your camera. Fill flash, on the other hand, is a different story. With fill flash, the sun (or other strong light source) now becomes the main light source, and your flash become secondary. Now consider you're outdoor with bright sun, so your subject is darker and you need to use your flash to "fill in". In order to expose the background properly, you're limited by a set of exposure, say f/2.8 1/1000". Remember most flash sync speed is limited to 1/60 - 1/250" as mentioned. Now in order to sync with the flash, you now need to drop the shutter speed from 1/1000" to 1/250", a total of 2 stops. So to maintain the exposure, you need to raise the aperture 2 stops to f/5.6, and in doing so sacrificing the shallow DOF that you might want to acheive. This is the main reason why high speed sync is important for outdoor daylight fill flash. Of course, if you don't mind/do portraitures then this won't be a concern.