Excellent service
My wife and I took a private safari, driving from Moshi to Tarangire, Serengeti, and then Ngorongoro on the way back. Our guide Jerry Bennett was excellent! Native English speaker, with degree in biology field, and manifest interest in wildlife large and small, as well as the flora. Thoroughly enjoyable!
We drove in a modified Toyota Land Cruiser with pop-top roof, which was the standard vehicle for almost all the safaris we saw on the way. Total mileage was 1800 km, most of which is on washboarded dirt roads, so you might want to bring extra padding!
Lodging depends on choice and availability. In Serengeti we stayed at Tukaone camp, which is a glamping setup using large tents, with flush toilets and running water. At Ngorongoro we stayed at Serena Safari lodge, which is a luxury hotel, including balconies overlooking the crater. Food was excellent.
Kili-Tanzanite is a small local company, but Andrew's service was excellent, and he dealt promptly and efficiently with any issues that arose. I highly recommend this company.