As for a RAW converter, I prefer Lightroom. Regarding lens correction, DxO gives you better performance and options. When it comes to Digital Asset Management, you will have to choose Lightroom. If you only need a simple file browser, DxO is o.k., but a bit cumbersome to use for only this purpose.
I am using both in my workflow with all my images going in and out of Lightroom and only very few actually being processed with DxO (when lens correction is badly needed).
Cheers,
Andrew