Having sailed both lines, I pretty much agree with most of the above as well. Entertainment is much better on "Celebrity" in my opinion, and the food is much better as well. On our last cruise on "Oosterdam" they served a lot of "comfort food". If I wanted meat loaf I'd have stopped at Cracker Barrel on the way to the port. Bottom line, I'd pick "Celebrity" in a heart beat over "Holland".
Marine, Pilot, Singer, Tuba Player, Carnival "Diamond"!