>the only difference I know is that references can be reassigned.

Uhh no. Neither the const pointer nor the reference can be reassigned. And you have it the wrong way around. References cannot be null, pointers can.

The other difference is that if you try and dynamic_cast a reference and it failed, it throws an exception where as a pointer just returns nullptr.

>That's not the case in Java and C#, which allow "null" to be a right-hand value for all types.

That's also wrong, primitives are not nullable.