re: A question on Caloris Basin
"The crater has huge mountains rimming it - how can it appear so
flat even accounting for different lighting between the two images?
In other words - why did it look so cool in 1974 and so bland in 2008?"
Not sure I understand your question. But as general rule any mountains are fairly insignificant in the planetary scale.
And also I don't think you should easily dismiss the affects of lighting upon how dramatic something appears.