Nairobi travel tips?

Phoenix Hi all, We are scheduled to travel to Nairobi for a 4 day trip to the Masai - around the Eid break in Sept. Have any of you been there? If yes, what are the potential do's and don'ts? Have heard conflicting stories about Nairobi being unsafe and others citing that its a great place to be. Thanks. Phoenix Also, if someone could advise what vaccinations need to be taken prior to heading down to Nairobi. Thanks. G to tha T you won't find adobe in nairobi, but they do have some spectacular hotels.