There are several things to like about the Oosterdam - the decor is fantastic, I really enjoyed the co-branding with America's Test Kitchen. Their on-board enterainment system (free) had a better collection of movies that I have on with Netflix & Amazon. The staff was friendly room was nice.
However, there is a major issue - the ship shuts down at 11:30PM sharp. I've gone to Alaska with Princess, NCL, Celebrity and now Holland America. I've never seen a ship where all the bars, all the clubs (1 club turned off music at 12:30 but services closed at 11:30) ALL the food - even the "late Night Buffet" closed at 11:30 sharp. The ship claimed room service was open after mid-night, however room service choose to disagree.
This I felt was in line with the very limited hours on facilities. Dining is a good example - breakfast opened somewhere between 6-7:30 (it changed daily?!) and generally was open for 2 hours before going into limited operation usually at 9am. I expect this from the main dining facilities but not the buffet.
Lastly, I wanted to mention the cuisine. The line cooking staff was primarily Indonesian. I was hoping for some quality local dishes, sadly I didn't find a single Indonesian item on the menu. The staff was good at cooking French or Continental Cuisine. However, once they got out of their wheelhouse (example Indian, Asian or Caribbean) I honestly believe their chefs are blindly following recipies they've never tasted. This narrorowness of focus is best illustrated when I had to explain to the chefs why I might want rice with the "Chicken Korma" they were serving.
Nice Cabin. However, the doors to the balcony are not sliding.