We took the Sky this past June 7th and had a great trip. Although our 4th cruise it was our 1st to Alaska. We lucked out with great weather which just made it better. My wife and I had a half of a suitcase worth of cold/rainy weather clothes we never used.
First, the ship is beautiful and we enjoyed the food and entertainment. Although the casinos were not kind to me. As far as the ports are concerned NCL provides an abundant amount of info on choices. We went whale watching in Juneau and took the White Pass Railroad in Skagway. Be prepared to take lots of pictures.