I used Jerry Tanzania Tours as my tour company to climb Kilimanjaro and was very happy with the experience. My tour guide was Brighton who was very experienced and knowledgeable. My group was awesome, I did not know them before I met them on the trip and I enjoyed every second with them. We did the 8 day Lemosho route and everyone summitted. It was not easy but had an awesome experience.
I definitely recommend following the recommendations for packing they give you. Avoid cotton and polyster fabrics because they are too heavy. Stick with a gore-tex shell and a goose down jacket. Also recommend Merino wool for first skin layer.
Jerry Tanzania is a great service, they picked me up from the airport and had already set up the hotel and trip. It's great if you do not want to be bothered with all the details of traveling and can pay a little more. No complaints