Overall, the DNA Descendants View is a useful tool and has helped me keep track of expected Y and mtDNA matches. However, I have noticed that there are issues with the view, particularly with dropping certain lines of descent.
Let's take the example of my direct paternal lineage exactly 10 generations back, which happens to be the immigrant from France to New France. The DNA Descendant view of René does include many lines of descent down about 10 generations, but for my own it consistently stops at my great great grandfather, Siméon Lavoie. I am ultimately able to find a view that incorporates my most recent paternal ancestors, but only by viewing it at René's great grandson, Louis. In contrast, I don't seem to be having similar problems on my mtDNA side. Viewing the mtDNA descent of my immigrant ancestor, Marie Sédilot, I don't have any difficulty finding my maternal grandmother (the number of generations from Marie to me is 12, rather than 10).
It is possible to get an error message of sorts if you choose someone who has too many descendants with DNA tests. One such example is the mtDNA descent of Marguerite Langlois. However, no such error message is displayed when I view the Y DNA descent of my paternal 8th great grandfather, which makes me think that there is a more subtle programming issue that ought to be addressed.
