if-else for Input.GetKey

For a binary case, where something can either go up or down, is it better to use

if(Input.GetKey(KeyCode.UP))
  GoUp();
if(Input.GetKey(KeyCode.DOWN))
  GoDown();

or with the else

if(Input.GetKey(KeyCode.UP))
  GoUp();
else if(Input.GetKey(KeyCode.DOWN))
  GoDown();

In my opinion, since a keyboard can handle 3 keys simultaneously, this will not have the same behavior. The first example will allow your object to go up and down, in the second one this will be go up OR go down, and if both are used, it will only go up.