While there were things I really liked on the Celebrity Silhouette, particularly the Spa Cafe for healthy lunches the cabin/bathroom size/ furnishings and the quality of the in room breakfasts (we were in Veranda room, Concierge class), I like Holland America much better because:
1) Drink service in outside/poolside and lunch buffet dining areas is very poor on Celebrity.... very hard to get anyone's attention to get a drink (do they memorize faces of who bought drink packages LOL?)
2) Overall, we found the food on HA much better. We thought LeCirque restaurant on HA much better than any of the special restaurants on Celebrity.