I went with Celebrity to Alaska before with my mom, about a decade ago. It was great. I decided to go back with my mother-in-law, and it's not great.
Some elements of the cruise are just wonderful. But there is SO MUCH wrong that I really can't give it a better review.
The wonderful: Some of the staff. The problem is that it's only SOME of the staff. On multiple occasions, I had a problem, would take it to a staff member, would be told that it would be handled, and then it wouldn't be. In general, the people who are working for tips and little else (waiter, room service, like that) are good to very good. Everyone else is doing an absolute minimum. Their goal is to get you to go away believing (generally incorrectly) that your problem is solved.
Needs a refit. See more detailed comments above.