I took the test and it was interesting stuff. The test that I took was from Ancestry and it cost me about $100.00. It was autosomal. I learned that I am about 86% African, with about 38% of my DNA coming from Cameroon and the Congo. About 32% is from Ghana and the Ivory Coast. About 7% from Nigeria; 3% from Togo/Benin; 3% from Mali; 2% from Senegal. The rest was European and Polynesian.
You can Gedmatch your results and get a clearer idea of what particular ethnic groups in those countries you come from. A more comprehensive test is provided by African Ancestry, wherein they test your maternal and paternal lines. I have not taken that test yet, because it almost $600.00, but I plan to do it later this Summer.
I think that the testing is really interesting and it was really interesting reading up on some of the ethnic groups that I am related to.