We decided to go on a cruise with our two children (ages 1 & 2) and our best friends and their two children (ages 1 & 5). We got rooms next to one another in a Family Room with veranda room and enjoyed our time on the boat. Here is what I learned about both the ship and traveling with young children.
1) Our veranda partition could not be moved due to the fact that we were on the end of the boat. Other partitions can be moved, however.
2) The service on Celebrity Summit was amazing. We were in concierge class, but everywhere on the boat the service was top notch.
3) Children under the age of 3 cannot participate in play areas that are specifically designated for 3+, even if parents supervise. The only area on the summit that my two children could play in was the toddler room, which was young for even my 15mo old. My advice would be to wait until your children are age appropriate for the programs, so they have some activities they can do without you.
4) Children in swim diapers are not allowed in pools. I found this out after I booked through a travel agent and would have definitely reconsidered. I understand the public health concern, however, it would be difficult to be in the pool if my children can't attend kids programs and I can't bring them in the pool. So this is what I did: My oldest daughter is mostly potty trained, so we felt comfortable bringing her in the pool without a swim diaper. For my younger daughter, I found a swim diaper online (Brand iPlay, website: Myswimbaby.com) that is required by law in many public pools throughout the US. The Celebrity Summit ended up having a large part of one of the pools that was very shallow water, so my daughter wasn't immersed and was perfectly happy to stand up there and play. I also noticed a lot of children with regular swim diapers and nobody seemed to be concerned. So in the end, it wasn't a big deal, but I can't guarantee that it wouldn't be on a different ship/cruise line.
5) Babysitting. Babysitting was advertised online and within our daily newsletter, with a 24 hour in advance request policy. We requested babysitting 3 nights and had a difficult time both securing the babysitters and getting them to call us back to let us know if we had them or not. We ended up getting babysitting twice, and they were great, however the experience of getting them was more difficult than it should have been.
6)State of the ship: The ship was old and therefore had old amenities (9 years I was told). It's going under a complete renovation in Jan 2012, which is very much needed!
Overall, I would recommend this cruise - both the destination and the cruise line. I would just be cautious of taking little ones as well as recommend going on a more recently updated ship! Also, do the research yourself - your travel agent will do their best to help you, but if you don't ask the right questions, they are not going to tell you about the things that may deter you from cruising!