The big decision you should make doesn't depend on specific itineraries, however. That decision has to do with a round trip cruise vs. a one-way cruise.

One way cruises all start and end in Vancouver BC and Whittier or Seward, Alaska, or (duh) the reverse. Leaving Vancouver, the ships travel through the Inside Passage, typically with stops at Ketchikan, Juneau, Skagway, and one other port - occasionally Sitka, or sometimes Hoonah (aka "Icy Strait") and all will have at least one cruising day near some glaciers - Glacier Bay or Hubbard Glacier (near Yakutat) are the most common. Then they will cross the Gulf of Alaska (typically at night since it's very big water) and arrive at either Whittier (a curious wartime relic of a town) or Seward. From Whittier or Seward one travels by land (bus, train, car) to Anchorage, for further touring or flights home. The ships turn around and do the same trip in reverse. All the Vancouver-Alaska one way cruises are seven days.

Then there are round trip cruises that depart from both Seattle and Vancouver. These are also seven nights, but they only travel as far as Southeast Alaska (the "panhandle") as they don't have enough time to go all the way to Southcentral (Seward/Whittier) and get back in the time allocated.

The Vancouver departures travel the full length of the Inside Passage while the Seattle boats generally travel to the west of Vancouver Island (i.e. on open ocean) in at least one direction (more often both) owing to traffic congestion in parts of the Canadian portion of the Inside Passage. Both the Vancouver and Seattle boats go through the Alaska part of the Inside Passage, and most call at the same ports as the one-way cruises. They may, however, provide more time at the glacier drive-bys, or offer an extra port, but that's contingent on the specific sailing.

The Seattle boats will all call at Victoria BC on the way back, in order to satisfy federal regulations requiring a stop in a foreign port on round trip sailings from US ports.

The advantage of the one-way cruises is that it gives you the opportunity before or after the cruise to visit other places such as Denali National Park or the Kenai Peninsula. But those both require several days, so if your time is limited to a day before and a day after, then the one-way trips might not be for you. If you can spare at least 4 days in Southcentral Alaska, then you can go places and see things; if not then all you're really doing is adding to the airfare tab.