I think it largely is going to depend upon how much walking you are comfortable doing, and to what locations, and where your room happens to end up being. For example, the two times at Disney World I most care about distances to and from a location at a resort are how far is it to my room and the buses, and how far is it from my room to my car. The reason is simply these are the two times I'm most likely to be tired. One times is transporting my luggage from my car and to my car, and the other times it's after I have already gotten back from a park, or even before I ever get there in terms of energy. For my family and I, where the lobby is would be most crucial after that.
That being said, when you look at the maps of Kadani and Jambo, I think things get a bit more clear in terms of distances. Both resorts, if you are walking their full lengths are massively large. There's no getting around that. They both are huge, and have to have large areas of land next to them available for the animals.
Here are three maps of the resorts from wdwmagic....
Jambo House
http://cdn.wdwmagic.com/imgstore/El...quality=90&encoder=freeimage&progressive=true
Kidani Village
http://cdn.wdwmagic.com/imgstore/El...quality=90&encoder=freeimage&progressive=true
Jambo House & Kidani Village
http://cdn.wdwmagic.com/imgstore/El...quality=90&encoder=freeimage&progressive=true
If you are concerned with these items (Parking, Lobby, buses, restaurant) above everything else, Kidani is the place where technically you "could" get the best circumstance. The reason is, if you happen to be in the first two segments on the right hand side, all of those are readily available. Sanaa and the lobby are one or two segments away and an elevator ride. Parking is directly below you, and the buses are sitting right outside (you can either go out the parking lot level, and walk up the sidewalk to the buses or take the walkway leading from near the lobby to the buses). No where in Jambo House can you get all of those four things near a room. Technically, the pool isn't even that far away, considering some distances. Now, this is all based on having a room in those segments, as without it, you'll probably have a walk on your schedule to at least something.
If you look directly at the Jambo House map, notice that bus transportation is barely on the map, and not near any of the rooms that overlook savannahs, and parking is not even shown on that map. Technically at the edge of the Jambo House map, there's still a small little island between where the map ends and the parking begins, as seen on the bigger map of both resorts. Kidani, the parking is under the resort. You take one of the four elevators, whichever section you are in directly down to the garage, and back up to your room. Technically, if you had the first availble space in the garage and the first room, after you get out of the elevator, your walk to and from your car is practically inconsequentual. That can't happen at Jambo House.
Now, before it sounds like I am being too critical of Jambo, Jambo does have more eating options, and it has more outdoor viewing areas of the animals. For example, there is the Arusha Rock overlook in the middle of the Arusha Savanna. However there is also an overlook tucked in behind the building at the Uzima Savanna, where also nearby is a large group of greater flamingos (this is close to the pool area). There also is a Savanna overlook area near the DVC booth in the lobby of Jambo House. Kidani also has overlooks which are very nice (one in back of the lobby and one in back of the pool area). One way however Jambo is different is that the stairwells in Jambo, are outdoors. Meaning that you can go up to the second to top floor, and look out across various savannas that might not be anywhere near the overlook areas, or your room. This may allow you to see animals that never come near your area. All the stairwells in Kidani are covered and indoor, and you can't see as much. The Jambo house ones though are quite beneficial for that. (In the map that shows both resorts, when you look at Jambo House, many of the ends of corridors have three circular straw overhangs on them, those are the stairwells) As you can see based off of that, that's a lot of places. When you walk down the hallways of those long segmented structures, there often times are windows overlooking the savannas, but when you don't want to deal with glare or rain water, being outside is best.
Each resort really is a spectacular marvel of engineering and are great and beautiful places. Probably the most glaring problem is just their physical size, and that if you get out on a far off limb, it can be quite a trek. Also I would HIGHLY recommend visiting both, as they have unique animals, and designs, and they really aren't that far apart. This isn't a thing unique to Animal Kingdom Lodge though, as some of the resorts have sizable walks attached to them. For example, Boardwalk, due to the boardwalk and the lakefront one entire side of the resort has no parking. If you happen to have a room near there though, it can be quite a walk too and from the parking lot. If you have any questions I've stayed and visited them often, though I don't know everything. Hope some of this wasn't too confusing, and helped a bit
