Depends. I usually run anything I plan on printing through DxO, esp. if I'm going to try to sell it. There's no other workflow that I've found that corrects as well for noise, capture sharpening, distortions, etc.
But, DxO has primitive organization and management abilities, so I still use Lightroom for those sorts of tasks. Lightroom also makes perfectly acceptable raw conversions for web and e-mail use.
Typically, I import my pics from cards using Lightroom. After I cull the obvious losers, if I find some shots worth printing, I'll open DxO and point it to the Lightroom catalog and process them into DNGs. Then I'll go back to Lightroom for printing, resizing, etc.