We did an Alaska cruise thru Princess in 2019 and it was amazing! Going in early April on NCL so will have more comparison for you then. (NCL I hear is a more casual vibe than Princess, and I do think I will miss the dressier stuff/high teas on the seas etc)
In terms of ports: Our favorite was Glacier Bay (hubby was enthralled and just sat on the balcony with coffee for like 8 hours and LOVED it). We did Icy Straight Point- and it was nice but probably the port I would drop off the ones we did. Gorgeous but small. They have some indigenous culture performances- but we ourselves live in an area full of indigenous culture so this wasn’t a big draw. Nice whale watching, but we personally saw more whales in Juneau.
Juneau we had some great whale watching and enjoyed the baby whales. Mendenhall
glacier was near but it has receded so much it is more in the distance.
Skagway we absolutely loved, and I don’t think I would do a trip with no Skagway myself. We splurged on the train to Yukon/Carcrosse (with bus down via Chilkoot), and it was amazing. I am super frugal but that one was worth the $$ to us. Stood on the back of the caboose and just took it all in as we ascended.
One thing: princess ends up in Whittier, which is beautiful but nothing but a cruise debark/embark warehouse, nothing to see there. Whereas some of the other cruises end in Seward which has a lot to offer, excited this next trip to see the Kenai fjords which is renowned for wildlife and Orca. (But haven’t experienced it yet). I remember being sad that we ended at Whittier instead of Seward.
You will have a great time regardless!!! Enjoy