Our first cruise in 2000 was the 4 day, because we had never cruised before. We have since been on the 7 day 3 times with the next one booked for 2004. We loved it and the extra days and ports are great. I think there are several things to consider, money being the biggest factor and how the kids will enjoy it. If you think this will be a once and done deal then I would go on the 7 day, if your funds allow you to take repeat cruises then try out the 4 day, you will be hooked. Our grandkids just love the clubs, ages 8 and 9, but some have reported that their kids did not. The only time I was paged the whole cruise in August was 20 minutes before the club closed on the last night. My grandaughter was in tears because she had to say goodbye to her favorite staff member.