I have taken the Y-DNA, mtDNA and Autosomal DNA tests from FamilytreeDNA. I have also taken the Autosomal DNA test from Ancestry.com (AncestryDNA). Y-DNA and mtDNA tests are very limited about what they can tell you about genealogy or ethnicity. They are interesting though. The Autosomal DNA tests have the potential to give you a broader look at both of those points. Both companies have their merits and expertise, but if your primary use for learning about your (statistically based) ethnicity, it doesn't matter which company you use. Furthermore, you have to be patient because population results are changing all the time. However, if you are looking for clues to relationships with distant branches (or even closer branches) of your documented genealogical tree, AncestryDNA is the way to go. It may be oversimplifying, but if one if testing with Ancestry, they are interested in genealogy. I've found that matches at FamilytreeDNA rarely accompany a family tree or any type of identifying information about the ancestry of the individual who took the test. For the researcher, this is no good. Too much to sift through with no clues. The AncestryDNA matches, though, most often have relevant trees attached to the results. I've confirmed several relationships and some of my other theories of ancestry have gained some credulity from the AncestryDNA results. This only works because people have taken the test and offered their trees for viewing. So I encourage everyone to take the test and upload a tree. Especially if you've got Kerry roots! Population results are a different story. FamilytreeDNA suggests that I am 100% Orcadian/British Isles. Although it is clear to me that this region is where many of my ancestors came from, it leaves out some pretty big chucks. This, of course, was disappointing. But it should be remembered that ethnincity predicted by DNA is not a cut and dried thing. It is based on statistical examinations of different populations across the planet. As these results are re-interpreted and new results emerge, this all changes. I haven't seen this happen at FamilytreeDNA yet, but AncestryDNA seems to be working hard. When I first took the AncestryDNA test, my results show that I am 88% British Isles 12% Finnish/Volga. This matches the documentation much better but I had hoped for some resolution. And a couple of weeks ago I got it. I was one of the lucky ones who got the preview of the new ethnicity results for AncestryDNA. Populations include: Ireland, Europe East, Great Britain, Scandinavia, Finnish/Northern Russia. I took the time to examine my ancestry from what I know, going back 7 generations (128 people) it was nice to see that the results were spot on. What value the results hold to you is a function of what you want to learn, what you know, and what is known about populations. All three will change indefinitely, so be patient and vigilant. William D Romanski