Addis is great. It is generally easy to get around and about. The food is excellent, the coffee even better. Ethiopia is great, the people are beautiful. The only difficulty, apart from areas of conflict is the languages which are not easy to pick up but with your background I am sure your brain enjoys new languages. For me the challenge was that I was there only very very briefly and I as far as I can tell there are not links between Amharic and other patterns my brain knows. This of course is what would make it interesting with enough time.