KHX1600C9AD3B1/2G has 1333Mhz clock, other one has 1600Mhz. That's the most important difference.
No, they're both 1600MHz. CMZ4GX3M1A1600
C9 and KHX1600
Their latency is also the same (CL9).
BUT there is one key difference: The CMZ4GX3M1A1600C9 is 4GB while the KHX1600C9AD3B1/2G is 2GB. This means that a single stick of the former RAM has twice the capacity of the latter.