I went with Leo 2 A6 because of its fuel efficiency compared to the M1A2, it's additional mine protection and the ease at which problems can be diagnosed and repaired. Also, the Leo 2 A6 is well built with very high engineering standards. In all of the other areas it's very difficult to seperate them.
I definately see the point made by Whispering about the fact that the M1 has been proven in combat. However, the Leopard 2 isn't just some run-of-the-mill design from a middling country. This is a German-made tank from the people who arguably have built the best MBTs in history. If any tank can be expected to perform it would be a German tank. The Germans are, after all, probably the best engineers in the world.
"An Emperor is subject to no-one but God and justice."
Frederick 1, Barbarossa