Anyone know? Is there any dis/advantage I'm not thinking of for either plan? I know the onboard booking discount would be 10%...but don't know how much the advance rates typically change up or down. We're going on our first DCL cruise in August, 2010 and plan to book either a Dream 5-night or a BtB (7-night total) for August 2011 while we're onboard. I know we could always call and rebook if prices drop, etc., but...trying to save a little hassle! Thanks so much!