I've been using DxO Optics for several years and it is a crucial part of my development process. I start with RAW images in DxO, move to Lightroom for further ajdustment, and then some final tweaking in CS5, if need be. Overall, DxO makes the RAW image better in many ways. The improvements are more subtle than expansive, but collectively improve IQ.
I am seriously contemplating moving from the D700 to D800 and will continue to use DxO should that happen.