One great distinction between Jambo 1BRs and Kidani 1BRs is the room. The Kidani 1BR wins hands down. The Kidani 1BR is about 100 sq ft larger than Jambo's, has more closet space, has two bathrooms to Jambo's one, has a master bath with tub and separate shower compared to Jambo's combined tub and shower (and the Jambo tub has a very high step-over to get into it), and has the master bath connected directly to the master bedroom while the bathroom at Jambo is across a hall from the bedroom, which hallway can be seen from the living room. Also, at Kidani you can get lower floor rooms (second or third floor) for more direct view of animals while at Jambo all DVC rooms are fifth floor (and sixth for club level).
Jambo wins if you want the larger lobby and much larger and better store, or want to be close to three restaurants, a good but quite expensive table service (Jiko), an excellent buffet (Boma), and a quick service (Mara) which has lots of seating. Kidani has only one restaurant, Sanaa, a very good table service. If you have a car, Jambo has parking in a large lot across the street from the front entrance; Kidani has ideal ground-level, under-building parking running along almost the entire building and with three elevators along each wing, you can always get a parking space fairly close to your room.
The Jambo pool is larger than Kidani's and has far more places to find shade, but it does not have a very long slide like the Kidani pool does, and Kidani has the water play area with things for kids anywhere between ages two and twelve, and its bar area has more tables than Jambo to sit and have a drink under a roof overhang that provides shade.
Both Kidani and Jambo share the largest Savanna, Sunset, which is very good. Jambo also has the Uzima savanna to the right of the building and Arusha which is inside the U of the U-shaped building. Arusha and Sunset are the best of the three but all three are good. Kidani also has the fairly small Pembe savanna, which many consider mediocre including because it does not have giraffes (it has a runt of a giraffe cousin called an okapi). You can request a particular savanna but it is not guaranteed (but at Kidani more than 80% of the savanna view rooms overlook Sunset and thus a request for Sunset is usually met if it is your lead request).
At both, you can have long walks to room from bus stop and lobby, but at Kidani it can be forever. The building is 2/3 mile long and the walk from an end room on its north wing to the bus stop is about the same distance as it is to walk from the base of Epcot's World Showcase to Germany. If you want to be near the pool at Kidani request either near the pool or near the Rafiki elevator (down that elevator to ground floor gives you shortest walk from building to a gate to the pool area); if you want to be near the bus station request near Community Hall or near the Timon elevator. Do not request "close to lobby." That is the most popular request made with the result that many do not get it and end up at the end of a wing as far from the lobby as you can possibly be. At Jambo, you likely should also not request close to lobby because those are not the savanna rooms with the best views.
The Kidani front entrance is about 1/2 mile from Jambo's. A shuttle (mini-van) runs throughout the day and evening for travel between the two. The actual walking distance from Kidani to Jambo really depends on where your room is, as it can be up to about 5/6 mile from a room near the end of Kidani's north wing, and only about 1/4 a mile from the Zazu elevator, the last elevator on the south wing.