I have a 2009 Diamond DA40 and have been extremely happy with the purchase. Diamond support is great over the phone and is always more than happy to assist my mechanic with any questions he has (he usually works on helicopters, he helps out on my plane to help me out).
My aircraft before was a Piper Seminole and that thing was a money pit. Getting rid of that thing was the best financial move of my life! I can't imagine ATP with their fleet of Seminoles.....must be an absolute nightmare for their maintenance crews.