Just a matter of how you want it to look.
PFS is very white, Black Diamond Blasting media is (you guessed it) very black, both are pretty clean and don't need excessive rinsing if any. Both are very uniform in size.
To my eye they both look completely un-natural.
I used to use construction grade sand from a local sand pit. Very natural looking, variety in side of grains & pebbles. But, very dirty, lots of rinsing.
I just capped a rank with Sakrete all-purpose sand $4.99 for 40#s. Not terribly dirty, some variation in grain size. Pretty natural looking, not as good at the local stuff in appearance but, much easier to deal with.
Sand Caps work over dirt because the dirty is finer in size and settles to the bottom. I don't know how sand works with gravel size substrate.