I have had my DNA tested with FTDNA with their Family Finder autosomal kit. But I also ordered kits for a number of relatives; my mum, my late father's brother, three of my father's cousins, three of my mother's cousins and my brother, whose DNA was also tested using the National Geographic's Geno II kit. (A couple of cousins have also arranged their own testing.) I haven't had the autosomal test done for all of them, yet, because testing is expensive, but I hope to do so eventually.
So far, although lots of autosomal and other matches have been suggested, I haven't managed to ascertain specific links with people I didn't already know. But that will come, I'm sure, and, regardless, the information that the results provide is fascinating.
Our relatives will not be around forever. Two of my mother's cousins who tested for me have since died. Maybe this is to be expected of people in their 80s, but, sadly, my brother also died, very suddenly and unexpectedly, so we never know who is going to be around to share their DNA and further our family research. I arranged for a number of tests to be carried out on my brother's DNA, so he continues to help me, even though we have tragically lost him.
One thing that we found interesting: Mum's mother was part Greek and when her cousin's Y DNA was tested, it confirmed that it belonged to a 'Balkan cluster'. Then Mum's cousin on her father's side had his Y DNA tested. We knew that my grandfather's side of the family had mainly English and Irish ancestry so we were very surprised when that line came back as part of a 'Balkan cluster' too - a different one. What a coincidence!