Skagway or Juneau...is one better for heli/dogsleding tour?

I want to say I dogsled acrossed the Mendenhall Glacier, but my cruise stops in Skagway first. Since this excursion is one of the most cancelled, my thought process was to book the excursion in Skagway and if it gets cancelled, to try and do it in Juneau.

Is there a huge difference between the two ports in regards to the scenery/glaciers in Skagway vs Juneau?

I would like to know as well