Just make sure you actually see it to handle before you buy. The sharpness you mention is critical if there are substrate fish.
I have been told that one can get black pool filter sand, as well as the usual white. Never seen it myself, so no idea on its roughness.
I am very happy with playsand. It is lighter in appearance under water than it is dry, but with lots of wood, plants, minimal light it is not bad. The corys seem to like it.
And in appearance it does replicate the stream sands in Amazonia, so it is authentic from that perspective.