During our stay in Johannesburg and Pretoria, we did three separate tours with Martin.  Each time, he was not only on time but early, and his demeanor and enthusiasm were infectious and inspiring.  Martin possesses excellent knowledge of the area, the wild animals (the Big Five and more), and the history of the country, even to where he could speak from personal experience.  I cannot recommend Martin highly enough.  He was warm, positive, friendly, and always welcomed us with a smile.  After the first tour with him, we specifically requested him the next two times. On our last day in Pretoria, we weren't even sure what we wanted to see, since we had covered many of the sites already, but we trusted Martin to take us to new places we hadn't even considered before. Highly recommended!