Own three, but have smelled all of them (however I only smelled Oud Musk once *I think*). Tough choice but it's honestly too hard to choose between M7, Black Aoud, and Dark Aoud without knowing the occasions you'd be wearing them in. M7 is the most versatile of the four, with Black Aoud being the least. However if it was for a purely formal event, Black Aoud would stand head and shoulders above the others.
All that being said, I voted for Dark Aoud.
