Candidly, although I know many people who I respect who have had the testing done, I do not see any value (TO/FOR ME) of knowing that information. I am very closely in tune with family medical predispositions, but if that was not the case I might feel differently. As to people who suddenly "feel different about life" because they have representation from certain origins/nationalities/races/backgrounds, that is something else I "don't get". I am who I am period. Most of that is about looking forward and trying to make and live intentionally integrity-based decisions and lifestyle, not looking back to where my predecessors may have come from.
That is just me, and I have no negative opinions of whether anyone else should/should not do it (my wife had the testing done).