I was just wondering if anyone has used this and, if so, how you liked it.  Since the center core rod does not go into the bottom cake board like a dowel rod system, what prevents the cake from sliding off of the board?  Thanks in advance.

Nothing, only the ganache or buttercream you put underneath. But it prevents to tiers above from shifting. The rods are smaller and easier to cut. Not sure which one I do prefer.... 

Thanks, Julia1812!