To add to Johneye:
1. What type of technology: CDMA, EVDO from ethio-telecom. Only good enough when outside peak hours. Also depends on which sub city in Addis you are. Some sub cities the coverage is almost zero.
2. ethio "hopeless" telecom have got 3G sim cards: again the quality of the coverage seems to depend in which sub city you are. Interestingly, I found 3G sim cards in my iPhone 4S to work simply fine in Awasa, but the 3G sim card does not work at all in an iPhone 5. You have to revert to 2G, which is archaic
3. Broadband again is available in certain sub cities only (suburbs), the other areas have got no coverage, at least this is what ethio telecom told me when I inquired when broadband would be available in my neck of the woods (Yeka Katama, Kfle, Karalo).
I found the best solution for my needs to buy a TP-Link 3.75G HSUA USD Adapter (about ET birr 1,750), purchased a 3G sim card from "hopeless" ethio telecom and voila - I could serve 24 hours with good coverage (also, it does not seem to chew up so much airtime). The unfortunate part is the ethio "hopeless" telecom does not offer internet data bundles (where you could purchase a 3G sim card, buy air time and convert this to data bundles) to make internet accessibility possible to a wider mass.
Also, speeds and accessibility seems to vary depending on the time of day: Saturdays and Sundays seems to be worst hit, it usually improves after 10:00pm, I have become a night owl and wait usually until 23:00 and then stay up until 02:00am.
As a caveat, the major hotels have WiFi capability and being naughty, I have discovered some of them have weak firewalls, meaning once you have ordered your coffee and you have got the password, you can pick up the WiFi signal up to 50 meters away from the establishment. Disclaimer: I won't disclose the names.
Finally, the EVDO seems to be working fine though and at ET birr 700 per month, it is relatively cheap.