For clairfication the above is not valid on Alaska sailings. All lines basically are "relaxed" and ship activies are way secondary to any thing outside the ship in Alaska. No party ships yet- and even Carnival is subdued with the majority of passengers on ALL lines middle aged and above. I recommend booking for what is OUTSIDE the ship- ports, time in ports, glacier, route, price. RCI/Celebrity are lacking in no Glacier Bay or College Fjords. There is no perfect cruise.
If ship is important then go with that- but don't compare sailing Alaska with sailing other areas- just not an issue.