There is some beautiful scenery on the long tour, however some of the areas can be pretty boring to look at. With the winters getting so cold in some of the areas you see there is not much that grows to see.
There are some beautiful lakes. It is interesting to see some of the stunted trees due to the harsh winters also.
It will all be up to your interests but the long trip can be a little long for some.
I go to Alaska on a cruise often and have done the long trip but once on the long trip was enough for me. I did feel the views from the train were better then the ones from the bus but that is just me.