23andMe are now willing to guess where one’s ancestors are from at the level of counties. For instance, as well as thinking I have 19% Swedish ancestry, they now guess that it is primarily from Västra Götaland County. Which is in fact where my current Swedish relatives cluster. Their guesses in Ireland center on Cork, with Limerick and Tipperary next door 4th and 8th most likely (of 26 counties), and those two are where the few 17th-19th Century relatives I know about seem to have come from in Ireland, so that also seems pretty good.
Much as I believe all that stuff about one’s body being full of cells that contain genetic code that is shared by one’s relatives, and about historic movement and mixing of populations being low, it’s awesome to actually see someone take a fairly good guess at what part of what country your obscure relatives lived hundreds of years ago by examining your spit.