Both the Dog and the 2160 are capable aerobatic mounts for basic aeros - neither are going to get you very far in competitions if you want to move up the scale.
Fatigue life in Dogs is a big issue. But as has been mentioned - the 2160 has it's problems too. The big difference will be in operating costs. The Dog has a CS prop and higher fuel consumption.
Both have had spinning issues in the past and both have spin recoveries which are different to what most people will consider the norm, but of course - there is no such thing as a standard spin recovery! (Debate expected!).