4runner speaks the truth. Every word is correct. Kigali is one of the nicest little cities in Africa. There are definitely expat cliques that you will either learn to navigate or get frustrated with.
I'd add a caution on dealing with the local population. Don't mistake a quiet, reserved nature for politeness. Due to many obvious circumstances, people behave differently in Rwanda. There is a strong inner rage that can manifest in many different types of passive aggressive behaviors. Tread lightly with the locals. Know their history and learn to adapt. Offend the wrong person and you will likely never know other than a personal lack of progression.