On washing the sand, I suggest filling a large bucket about half way with it, then filling the rest of the bucket with water. Move the sand around for a few minutes and then dump out the water. Repeat that about 5 times, and the sand will be really clean
If you want pros and cons:
Pros: I personally think it looks really nice and certain fish love to burrow in it.
Cons: Slight currents will mess it up, it's can be hard to clean, and can be dangerous if it builds up in a corner or mound and isn't flattened out. It can also be hard to plant it, depending on what you want.
So it kinda depends on what kind of setup you're using it for