It doesn't work and play well with P9 which is licensed to me personally.  The Pro versions I have are licensed to my employers and they will not allow "unauthorized" plugins and scripts (their terminology) to be added so I can't attest to how well it does or doesn't function with the 64bit versions.

I don't know what the others who have tried it with the Pro versions have found but I have read commentary over at the DAZ forums that the DSON importer needs "an off switch" to stop it continually applying active morphs to all the clothing items once you click on it the first time.

You might want to ask over at the DAZ Poser forum to see if you can get someone to give you more help.

Sorry I can't be of much more help as I pretty much gave up on using the importer shortly after it was released.

While it's time consuming to do, using the cr2 exporter from DS and creating a cr2 for Genesis works much better in Poser than going the route of importer. 

If you haven't tried it, you might want to.  The only thing I will suggest is to rename the obj file for Genesis something more familiar and change it in the cr2.  DS's exporter gives it some long ridiculous designation.  I also found using binary morph targets (pmd's) make for faster load times, especailly if you have more than jus the very basic morphs.