Those V12 Mercedes are known to be the best bargains, when slightly used. Very hefty depreciation.

I'm sure the 599 can hold its value signficantly better than the CL600, in both $ and %.

It's all subjective as we all have different needs. Gone are the days of wanting a car with so much power the chassis cannot handle. The 997TT can handle its power but it's a little loud. What will be nice is having an car with the effortless power, quietness, comfort features of an AMG, with the driving dynamics, traction, braking of the 997TT.