I know that when we have fixed arrangements about a plan, we use present continuous.
Example: We are visiting X city next week. Would you like to join with us?
-> All things have been arranged. I already decided the time, bought flight tickets...
But when there are not fixed arrangements about a plan. We use be going to or future continuous instead. Right? So what is the difference between "be going to" and "future continuous" We only decided to visit X city but haven't made any arrangements.
(1) We are going to visit X city next week. Would you like to join with us?
(2)We will be visiting X city next week. Would you like to join with us?
Is that "be going to" is more certain to happen than the future continuous here?