CLS63 or G55?
 

I'm close to purchasing a new car for myself, and I'm stuck between the CLS63 and the G55. It's been an exhaustive process where I'm going back and forth on the practicality of the G55(starting a family) and pure speed of the CLS63.

Anyone have any suggestions? or better yet, why I shouldn't pick one over the other? Faults of each car?

PS: If I get the CLS, it is most certainly going to get a Kleeman or Brabus tuning upgrade.