We have stayed in both too. My kids preferred Kidani. They liked the upstairs sitting area, they liked the two levels and being closer to the Kidani pool. I have to admit that the floor to ceiling windows at Kidani gave the GV a grand feel.
I preferred the Jambo GV for the reasons the PP said. The Master IMO is nicer, I liked the one level floor plan (and that worked better for my elderly parents) and we all liked the pool table. I also have to agree with the PP, the balconies at Jambo are bigger and nicer than Kidani. My parents, DH and I really enjoyed our morning coffee/breakfast on the balcony -- my kids were like *meh* -- LOL
They are both really great rooms. If you are going to use the Kidani pool amenities, maybe staying on the Kidani side will work better for you and your family. You can shuttle over to Kidani from Jambo, or walk, but it is still not as convenient IMO.
A GV stay is always exciting! I have my first extended stay at a GV coming up in Aulani. The first question DD asked me was "is there and upstairs?" LOL Kids!
Happy planning. Have great trip.