I like it for the reasons Jen stated. Doesn't break down as fast as Brightwell.
I usually mix it with some sort of sand so there's something with a little weight to hold plants down. Even if you have a deep substrate layer, it's really light weight and it can be tough to keep plants rooted in it when you first add them.
Or get a good pair of tweezers to plant deep enough and skip the salt ‘n pepper substrate look. (Sorry, Becca. Still Love ya!)
I guess it would do that in a rimless tank. In my 55, it just all sits on top and the "salt" is below the bottom trim, so I just get the dark substrate. Of course, if you fancy, black sand is also an option