If you like to have a quick service nearby, then Jambo House would be the choice as there is no quick service at Kidani except for a limited menu at the pool bar.
Other than that I think the big difference is that Jambo House is a cash resort and has the noise and volume of people to go with it. With two table service restaurants (one which is quite large, Boma) many people from other resorts are coming and going at Jambo House so that means the lobby is often crowded and noisy.
I like Kidani because the smaller lobby seems more inviting and definitely makes me feel like I'm home. The rooms at Kidani are a little larger and they do have an extra bathroom in the 1 and 2 BRs. The pool and water play area at Kidani is made for families. Except they didn't consider how many would need somewhere to sit in the shade.
There is lots of shade at the Jambo House pool. But there's not a water play area. There is a regular small play ground. The 2 BRs at Jambo House are only lockoffs. Kidani has dedicated 2 BRs.