Another thing to consider is that there are different animals on the 3 savannahs. My daughter HAD to have zebras (hey, she's been a zebra for two Halloweens!) so the CM I made my reservation with told me she'd note that in my reservation and the people at the resort, who know exactly what lives where, would take it into consideration. We got a great room on Arusha Savannah, which is where the zebras live. Arusha also has wildebeest, elands, and giraffes.
Others may remember more exactly than I can, but I think Uzima had all the cool antelope-type creatures with horns... bongos, gazelles... and if you wanted to see ostriches, you had to have the Sunset Savannah.
I think Allearsnet.com has a list of the animals on the 3 savannahs somewhere.