Both Dr. Kauten and Dr. Chen are well known and regarded here in Atlanta, so you should be in good hands either way. Dr. Chen may be more of an Aorta specialist, but that's based only on what I've heard, you've probably already learned much more by speaking with them both directly.
My surgery was done at Emory by Dr. Robert Guyton, the "elder statesman" so to speak of Atlanta heart surgeons, who helped train them both. I have nothing but good things to say about my surgical experience at Emory, and I believe it's still the top rated (US News) heart center in Atlanta, but I've also heard good things about Piedmont and St. Joe's (particularly ejc61's surgeon) as well. If you haven't already, you might try to do a search here using both surgeons' names (Chen and Kauten), they have been mentioned more than a few times.
Best wishes to you moving forward and welcome to the community - this place is a great resource for any other questions you might have.
