It's the same things as Eco Earth... just a different brand.
I've never used the coco fiber for my snakes, but people do use it. I honestly don't know what the risk level is, but people against using it will say it easier for impaction to occur. I guess the theory being that it sticks to the food prey when the snakes eats it. The larger chunks of ReptiChip are less likely for that to be swallowed. Again, never tried it, but it IS used.
I think it "looks" nicer the enclosure... looking like loose dirt. But also probably a little harder to clean.
Just my 2¢.