Our family went on the Alaska Inside Passage cruise from Seattle, with 20 people (12 adults and 8 children) taking up 10 cabins on the Aloha deck.
On ship amenities, having taken other cruises before, the Ruby Princess did not strike us as grand, because the ship's common areas did not have a lot to offer in terms of amenities and activities that newer ships would have. For a huge ship that is around 110,000 tons, it offered basically the same common area as a ship 2/3 its size. On the positive side, the ship was maintained very well, and all areas were very clean. For an older ship, nothing looked tired.
On entertainment, we skipped most of the entertainment offered, including most shows at the Princess Theater, and the few shows like the magic show at the Explorers' Lounge and a musicale at the Princess Theater that we attended were mediocre. The only one that quite impressed was the magician at the Princess Theater. Movie under the stars was enjoyable especially for the kids, especially with a constant service of warm drinks and cookies as you watch new movies by the poolside wrapped in a blanket and soaking in the hot tub.
Cabins are very small. Toilet and bath really tiny. However, for 2 people the cabins are sufficient. The steward did a great job every day.