Ben,
If I lived in Melbourne, it would be hard to turn down Royal Melbourne, but I really liked Kingston and can imagine why it might be the better club to join.
Besides that, the green complexes, bunkers, vegetation, etc, are exquisite. Normally, I like some elevation change both for shotmaking interest and exercise. But, Kingston is so good I am not sure it matters.
One other point: I came away from Kingston wondering why we don't see more places like. Is it just the Sandbelt soil conditions that make it hard to replicate?