I've stayed here twice in the past two months. And I travel all over Africa, at least every three months. So there's my cred and here's my take:
This is a really good hotel, by any standards. There are a few quirks, but overall a great place to stay. Free shuttle from airport, nice large rooms, beautiful grounds, decent restaurants, really nice (if kinda slow) service.
Tips: yes, the AC sucks. Leave your balcony window open for some nice cool Addis breezes. The Indian restaurant is by far the best of the options. Join Starwood's membership program so you can stay on the executive floor, enjoy the daily free cocktail hour, and have both breakfast and wi-fi comped. Taxis are outside the main gates, but if you're willing to pay a bit of a premium, they have a very reliable fleet of cars. Enjoy the many many tv channels from all over the world.