My husband and I chose to climb Mt Kili with the operator Climb Kili. Based on their reviews they were safe, had a great success rate, and very knowledgeable of the mountain, terrain etc! We chose the 7 day Machame route. We were beyond pleased with our guide (Seraphine) and assistant guide (Japan) along with our chef and porters. We had amazing meals, never felt unsafe or too tired, and always knew the planned routes, timetables etc. We successfully made it to the summit, which was the most amazing accomplishment! (We do advise getting Diamox, acclimatization pills - they helped greatly)! We'd highly recommend Climb Kili to others who'd like to take on the mountain!