A small country that has decided what it is for
Short transfers are the whole argument for Rwanda. Kigali to the lodges near the trekking sectors is a drive of a few hours, not a full day on rough roads, which means a three day trip is genuinely worthwhile rather than a rush.
The conservation model is unusually well documented. Permit revenue goes into the park and into the communities bordering it, and the rules on group size, contact time and distance are enforced rather than published.
Kigali itself is worth a night at either end: clean, easy, with a serious memorial and a good food scene. And Lake Kivu turns a single objective trip into a rounded week.