We have only cruised 5 or 6 times, but we have experienced a number of cruise lines. We anticipated that Holland America would be at the 'high end' of cruise experiences but that wasn't our experience. I should say that many of the issues stated in other reviews were not issues for us - the air conditioning worked; we had an aft stateroom with balcony and no problems with soot, and only very slight vibration when the ship started up; our on-board credit was in the room etc etc. The staff were universally friendly and helpful. The decor is a little old-fashioned, but that isn't a major issue for us. The issues for us were: the food and the 'hard sell' atmosphere.
First, the food. We found the Lido buffet restaurant to be a very stressful experience. Waiting in queues; fighting through crowds; some of the food stations were not organised as we expected (baked beans on the Asian section?); lack of tea cups; my partner's order was overlooked and then everything he had ordered was finished. The food itself was cafeteria quality, the carveries served grisly, cheap cuts of meat.
In the restaurant, the menu was good, but the delivery was often poor. Overall, the food was far too salty. Eventually, after complaining about this, my partner was offered a low sodium menu, which meant he had to choose his meal the previous night. Really, all that needed to happen was for the sauce to be served separately. The ingredients were not as expected and were inconsistent in quality. Steaks were not cooked properly; a 'New York' cheesecake was made with Ricotta which provided entirely the wrong outcome; a Bomb Alaska was served with egg whites which were not set at all. On the plus side, the bread rolls were superb.
A little old fashioned, but clean and well looked after. There was a little vibration when the ship started up, but that didn't worry us. A tiny amount of soot on the balcony one morning, but very little.