Bummer. Now you guys got me thinking, and there goes the blessing of ignorance.
I knew I can get better results if I move all the sliders to the left in the Raw Fine Tuning, especially with problematic shots, and I have yet to look for some examples that Keith described, and also re-process some of my images.
A quick comparison showed DPP < Aperture < GraphicConverter, but the latter was not as flat as Aperture, so with a little tweaking Aperture might be on par. I would hate to give up the convenience of using only one tool, but I will do some more comparisons with selected shots.