Upgrade in terms of what? If thats a pure silver cable vs spc of the smoky litz, then the prevailing wisdom will be that pure silver will emphasize microdetail and clarity, while silver plated copper with have a bit more emphasis in the low end, while still being nicely detailed. Of course, I personally think that most sound changes from cables are either due to impedance differences or are minor at best and for me what I would look for most in a cable is ergonomics and to a much lesser extent, looks.
So, I would think its likely a matter of which material you are looking for in a cable, pure silver, or silver plated copper?
Unfortunately, I havent used the fiio cable, but I can say that out of the campfire cables I have tried (had original cables with the vega, polaris 1, and atlas) the smoky litz is the nicest cable they have made. No memory wire, nice looks, and its very very supple and not prone to microphonics. Campfire does however make a pure silver cable too (the cable that comes with the atlas). Its a nice cable, but not quite as supple or soft as the smoky litz. It has some slight microphonics, but its not too bad, but since its a bit stiffer it also tends to hold shape a bit, which is not as nice when you go to unroll it. And it has no ear guides at all, which may or may not be a plus for you. Its also $250 dollars vs $99 for the smoky litz.