Rongai is the only route on Kilimanjaro that approaches the mountain from the North. This route requires longer transport and it is less visited, so it can cost a bit higher than the others.
You can finish Rongai route in 6 or 7 days, but note that shorter trek does not offer acclimatization day to accommodate high altitude conditions. This route might be not as attractive as Machame or Lemosho, but it offers amazing view of Mawenzi and Kibo Peak.
The success rate is relatively high, with 70% – 80% chance to reach Uhuru Peak. Rongai has gradual and easy path, with a very steady rise, and its is much drier than any other route on the mountain, so you should not expect much rains on your climb. The sleeping is in tents, in a very well organized camps. Descend is at Marangu Gate.