Overall, we had a great trip. I did the inside passage in the 1960's, and the whole trip was foggy with cold rain; definitely no fun. As a result, we did not pre-book any excursions until we got on board and knew what the weather would be. The weather was great, so we spent a lot on shore excursions. Some were worth the price, others not so fun. We would have saved a lot if we pre-booked them independently before the trip, but I didn't want to pay for a trip in the rain. We prefer outdoor, hiking type things which would have been awful in 54 degree rain.
The rooms are old. We had a veranda room. Some things definitely need updating. There was only one outlet in the room, very inconvenient if you want to charge things. The water in the shower was cold if I waited too late in the morning - I really needed to shower before 7:00 if I wanted a warm shower. The ventilation system was inadequate - we slept with the patio door blocked open, which they said not to do, but we made the choice to breathe fresh air. Other people said their room were too hot and stuffy, and some said they were too cold. Obviously, Zaandam has an old HVAC system. The bathroom sink was cracked. The room steward was great, and the room service was impeccable, and the room was always clean.
Dining was okay, not super. The Lido deck for breakfast was good, but if you wanted an omelet, the wait was a joke. One cook, no helper. The attendants in the Lido were very good. The main dining room was okay, but the food was certainly not deluxe. Do not order the halibut - it will come overcooked and tough. Waiters were inconsistent - some were great, some were very inattentive. HAL has a policy of allowing one bottle of wine to be bought off-ship. That means at the embarkation port - if you buy a bottle at one of the other ports, they confiscate it, and give it back to you when you leave.
This is an older ship. The cabins are comfortable, except that the ventilation system is antiquated. Our room was too hot; other passengers complained that their room was too cold. There is only one outlet in the room - my wife uses a CPAP machine, and the outlet was on the opposite side of the room.
The beds are really comfortable, the towels are nice, and the room was kept spotless.