I'm for the M1A2 as being the best tank about... The Leopard 2
does not quite cut it... they only look similar on paper but the
M1A2's IVIS ability allows it far greater coordination and SA then
any other current tank (M1A2s can be intergrated with the force 21
systems), including the Leopard 2.
Armour is superior as well, besides the Chobhamm, the M1A2 has the
extra DU layer that gives it the best protection armour wise,
though for survivability in event of penetration, the Isreali Merc
is far ahead of any western tank.
It seems that the main reason people pick the Leopard over the
Abrams is because they look similar on paper, but the Abrams has
the turbine engine. Said and done, the turbine engine is no less
then an ordinary one and is in fact the most fuel efficent engine
when going full out (though it burns almost as much fuel while
idle). The use of the turbine was selected on basis of
understanding the advantages (greater realibility, less weight,
maintainence ease) and the limits (fuel consumption).