We were also on the Zebra Trail - room #4435. I would highly recommend this section of rooms. We were on the side of the savannah with the giraffe feeders and we saw all of the other animals daily. We were the last room in that section and if you look at a map, we were right around the corner from the elevator that went down to the ground floor where Simba's Cubhouse was and the door to the pools. Also it was just a short walk outdoors to the foodcourt and restaurants. We did not have any obstructed views by trees or Arusha Rock. I would think that if you were too close to the lobby, the Arusha Rock area would obstruct alot of the savannah. We could see almost the entire savannah from our room. I do think that if you were further out on the wings, the trees might present a problem with the upper floors. I cannot complain about one thing with our location. There was no noise from the hallways even though we were close to the elevator bank. The zebras and other beasts seemed to move around from one side to the other. However, for a good look at the giraffes, I would ask for the wing that we were in ( to the right from the lobby).
Also, remember that the lobby is actually on the third floor. Sometimes it gets a little confusing. I would be happy to answer any other questions you might have. Also I have a map I could send you of the rooms if you like.