Those of you who know cruises, help me out.

I'm getting married in April, looking at a cruises for possible honeymoon ideas. I found two that work well with our schedule, one on Celebrity (ship: Constellation), one on Holland America (ship: Zuiderdam). Both would be in the Caribbean.

Ports aside, is there a reason to choose one of these two cruise lines over the other? If so, have you had experience with both? They both look pretty good to me...