Kigali feels calm and clever. The city is clean. People smile. The air is cool because of the hills. Most travellers enjoy the small cafes and the busy markets in Nyamirambo. For some, the strict rules and quiet nights will be amazing. Arguably not the best if you want loud parties every night.
Cost of living is fair. Cheaper than many Western cities but cafes and groceries can add up. Internet is pretty good. I worked from a co working space with fast Wi Fi and met other remote workers. There are also reliable 4G spots around town.
Things to do are great. Day trips to gorilla treks or Lake Kivu are easy. I read about people playing beach volleyball at Lake Kivu on weekends. There is an active startup scene and friendly expats. You can join meetups, coding nights and coffee huddles. If you want a safe, tidy base with nature close by, Kigali might be your kind of place.