I agreed with you on AncestrybyDNA. (By the way, they use 175 AIMs not 147.) However, given the great deal of admixture that almost all African Americans have in their genetic make-up, I think it's rare for the DNATribes analysis to provide any information of substance for an individual in this group. AncestrybyDNA hits the matter head-on with percentages from the four biogeographical regions of interest. For most African Americans that's sufficient to confirm or put to rest oral history/suspicions.

I also think that the Y-chromosome and mitochondrial tests are useful. I have established haplogroups for seven of my eight great-grandparents and two great-great-grandparents (not covered by the seven). However, most people are not in a position to track down enough cousins to do this. They end up getting too worked up over just one Y-chromosome test or one mitochondrial test. Each of these tests represents just one branch in a complex (especially for most African Americans) tree. The "bottom-line" test AncestrybyDNA, along with as many ancestral haplogroups as one can establish, is my recommendation for most people. Do the standard genealogical paper chasing. And then study, study, study...