I am not sure what the purpose of you and your brother taking all the tests. DNA testing is a definite expense. The only reason I could see to take all of the tests available is curiosity. Well - that is a lot of money to spend for the sake of curiosity.
DNA testing is very effective if you get the specific tests done to answer your specific interests and concerns. I administer a Surname site. The goal of the site for me is to find my specific paternal line, but also to better align the variations of the surname that we have seen.
I have been doing research on this line since 1999. I was having trouble finding anything at all prior to my gggggrandfather - before Missouri statehood, when the area belonged to France and then Spain. When Illinois was considered a country - and prior.
There are many of us researching the same lines and we keep running into each other research-wise, but we weren't able to break through. So one of the women I had been researching with since about 2004 or 5 had her brother take a DNA test. It turns out he is an exact match to my father.
Learning this helped us to focus our research efforts together. We met recently (2 weeks ago) in Missouri (I'm in California and she in Colorado) and we did a geneology road trip. We finally - after all these years were able to get substantiate one more generation and we identified several very rich areas to continue - but we need better documentation still.
The DNA testing forced us to really look at our ancestors to find how we are related. As we learned more on our 10 day trip we hypothesized about the information we were finding and how it all could fit together. We spoke about the possibilities on several occaisions throughout the trip.
Right now we have a promising hypothesis we are working on. It looks as though our gggggrandfathers were brothers based on what we have at the moment. Our goal now is to find the documentation to substantiate it. We found someone that has the potential to be the next ancestor back but we are not sure. It is easy to get distracted by multiple possibilities, but if we can find someone in that line that has done a YDNA test and it proves positive then we will significantly narrow what we need to research.
We will pursue the documentation, but as we unearth a trail, part of the strategy is to test other males in other surname lines to determine if we may be in their line or not - of course if that comes along with 3 or 400 years of good documentation on the line, then that will save us decades of research and provide a better path for additional documentation.
I am pretty new to DNA. I don't know how to use all of the current tests that are available, but I pretty much understand, at least at a basic level, the importance of YDNA in the surname. I understand the importance of allowing a broad range of variations participate in geographical studies because we didn't all end up in the family we were born to nor the place we were born.
Depending on family dynamics and numbers, health issues, deaths, work / income needs, children may have lived with relatives or lived with friends to learn a trade, care for a neighbor or feed a community. Some folks will take the tests to understand migration patterns and find out if they do indeed have indian blood or not.
DNA is the most wonderful tool if used strategically to serve the purpose and need you may have. It can really do wonders for genealogy.
Laurie C. Angel (BTW my 'cousins' name is Angle)