My priority would be the wonder of Alaska that I was planning to go see.
Not all cruises and cruise lines are created equal.
I am thinking that Princess might be the only cruise line that offers cruises that include both Hubbard Glacier and Glacier Bay.
Their Voyage to the Glaciers, SOUTHbound, from Anchorage/Seward, is huge on my bucket list.
I did the southbound on the Coral Princess. We had the most spectacular weather - it actually didn't rain at all, until the final sea day going into Vancouver. This is exceptional, though, as southwestern Alaska is actually a rain forest! (And Princess's Voyage of the Glaciers sail between Vancouver and Anchorage/Whittier, not Seward.) We went into Glacier Bay, saw the tops of the glaciers, which is unusual, saw a number of glaciers that usually are fogged in. So much so that the Park Ranger on board was excited, saying that she hadn't seen some of the tops in years! We got very close to Hubbard Glacier, too.
The round trip cruises from Seattle, if they're only 7 days, don't go far enough north into Alaska. Round trip to Vancouver is better, but the best scenery and the most varied scenery are on the one-way trips. And you can only do a land tour (which we didn't have time for) on the one-way trips.