Upload & Sell: Off
I use CS5, Aperture 3.3 and DPP. They're all good tools. With that said, I use Aperture 90% of the time for RAW conversion and basic tweaks and CS5 for heavy processing and printing prep. However, as chunky as DPP is, it sometimes will effortlessly nail a troublesome RAW conversion that bests many minutes of toil in ACR or Aperture. So it's a great tool to keep for when you need it. And, yes, the lens distortion and optimize feature are amazing. Sometimes I use DPP just for those things. I really wish Canon made these features available as PS/Aperture/LR plugin.