Jambo if you want a resort with restaurant options, a huge lobby and lots to do. Kidani if you want to walk all day, enjoy a lobby the size of a living room and don't care about restaurants (while Sanaa was good, it's not counter service which comes in handy with kids). I know people say you can go back and forth, and you can, but with little kids in tow we didn't find it convenient. The walk to the shuttle from our room, waiting for the shuttle, getting over to Jambo and getting two sandwiches and then returning via shuttle to our room took me 50 minutes round trip. Not my idea of fun.
IMO, the only advantage to Kidani was that its the first pickup for the park buses so you don't have to fight for a seat.
I know some people love Kidani but it was not for us. To each their own, that's what makes DVC interesting. Conversely I really liked Jambo.